club leader notes
Foreword
Most people have probably learned something about forensic science from TV series such
as Silent Witness. But how do these fictional depictions compare with real forensics? One
difference stands out: there is not one single person among all the forensic scientists
who does everything, as is often the case on TV. However, the field of forensics does cover
a broad spectrum of sciences, which makes it a very exciting and varied topic not only for
students but also for teachers. As well as the crime-scene investigators who find, collect
and protect any evidence from the crime scene and send it to the crime lab, there are also
various other forensic scientists who specialise in particular detection methods, such as
latent print examiners – whose expertise lies in examining fingerprints, palmprints and
footprints – and forensic odontologists – who help identify corpses by matching dental
patterns with previous X-rays, dental casts or photographs.
Forensic science series on TV are still powerful and can even have an impact on real
forensic scientists. The public often expect that real forensic scientists have to come up
with all the answers within a very short period of time, which is not always possible. Dr
Steve Bleay works as a Scientific Officer for the Fingerprint and Footwear Forensics Group
at the Home Office Scientific Branch (HOSB). He says that a lot of forensic techniques take
a lot longer than they seem to take in TV dramas, but there are some cases in which real
scientists can get the results as fast as the fictional ones.
‘For instance, the National Policing Improvement Agency (NPIA) is introducing wireless
transmission technology that enables powdered marks developed at a crime scene to
be directly transmitted back to a fingerprint bureau for rapid identifications to be made.
However, it is not only important how quickly you develop fingerprints but also that you
don’t miss any marks. Getting this balance right is important.’
Steve Bleay, HOSB, 2009
Based on evidence that can be left at real crime scenes we have chosen three activities
students can do to identify the thief in our crime story, which has been specifically
invented for this box.
We hope that this brief introduction has motivated you and your students to explore the
crime detection techniques you can find in this box. Don’t forget, these activities and
extension ideas can be used to help your students gain a Bronze CREST award (for more
details go to sciencemuseum.org.uk/scienceboxes). And next time you are watching a
forensic procedure on TV or in the movies, try to recognise which elements could be part
of the reality of modern forensics and which are just TV forensics.
Have fun with the activities and enjoy catching that thief!
Yours,
Science Museum, London
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Club leader notes crime lab
Contents (click on the page number to go straight to that section)
Activities
Page
Activity 1: Fuming fingerprints
Aim of this activity
5
Materials
5
What to prepare before your club session
6
Health and safety information for your risk assessment
6
How to run the activity
7
Top tips
10
Ideas for discussion with students
10
The science behind the activity 11
Links to everyday life
14
Links to the Science Museum
17
Links to the National Curriculum and Scottish Curriculum
17
Extension ideas
19
Activity 2: Swipe card
Aim of this activity
20
Materials
20
What to prepare before your club session
21
Health and safety information for your risk assessment
22
How to run the activity
23
Coding system sheet
25
Top tips
26
Ideas for discussion with students
27
The science behind the activity
28
Links to everyday life
29
Links to the Science Museum
31
Links to the National Curriculum and Scottish Curriculum
31
Extension ideas
34
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Club leader notes crime lab
Activity 3: Casting
Aim of this activity
37
Materials
37
What to prepare before your club session
38
Health and safety information for your risk assessment
38
How to run the activity
39
Top tips
43
Ideas for discussion with students
44
The science behind the activity
45
Links to everyday life
47
Links to the Science Museum
49
Links to the National Curriculum and Scottish Curriculum
49
Extension ideas
51
What’s on the website?
Posters 53
Film 53
PowerPoint presentations 53
Student logbook 54
Reorder sheet 55
Links to websites for further research 56
Information for the crime story Version 1: Fuming fingerprints, Swipe card and Casting
58
Version 2: Fuming fingerprints
69
Version 2: Swipe card
72
Version 2: Casting
79
Thank you! 82
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Club leader notes crime lab
Aim of this activity
Materials
In this activity students will develop a
fingerprint using superglue vapours in
a special fuming chamber. The fuming
chamber provided in the Crime Lab
box allows students to conduct the
experiment safely. This activity allows
students to get to know an exciting way to
make invisible fingerprints visible that is
also used by real crime investigators.
This box provides enough materials for 5
groups, each consisting of 3–4 students.
Each group will have the following
materials:
A
1 x orange fuming chamber base
B
3 x plastic cups (fuming chamber lids)
C
5 x circular metal discs
D
1 x grille
E
1 x crocodile clip
A
B
D
C
E
We have also provided the following
materials for you to give to the groups:
F
1 x tube of superglue
G
1
x plastic sheet for fingerprint
samples
G
F
You will need to provide:
Information about the suspects for every
group (see page 58 or 69)
1 x power supply (6 V) for every group
Disposable gloves for every participant
1 x magnifying glass for every group
(optional)
Goggles for every participant
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
Fuming fingerprints
We have provided you with two different versions of our crime story: version 1 allows
you to use all three activities from the box as one longer project (so your students need
to do all three activities to find out who committed the crime) and version 2 allows you
to deliver each activity as a stand-alone session (so students can identify the thief after
any one session). This also means that you will need to prepare the session slightly
differently depending on which version you choose. See page 58 or 69 for further
information about versions 1 and 2 and how to prepare for each.
Health and safety information for your risk assessment
From our extensive testing in clubs around the UK, we recommend the following
elements are considered in your risk assessment for this activity. However, you
know the needs of your group and the environment you are working in, so we would
strongly advise you to consider if any additional elements apply in your particular
circumstances, before you run this activity. If in doubt contact CLEAPSS
(cleapss.org.uk) for further information. All resources should only be used under
adult supervision.
Activity element
Information for your risk assessment
1. Superglue
Superglue carries a strong risk of skin adhesion, so should
be used with care by an adult wearing gloves. If skin contact
occurs, wash with warm soapy water. Do not force bonded
areas apart and seek medical advice.
2. Superglue
vapour
Superglue will produce vapour when heated and there is a risk
of irritation to the eyes and nose. When doing the experiment
keep the plastic cup over the base until it has cooled. Place the
fuming chamber in a fume cupboard before you remove the cup
to get the piece of evidence out of the chamber. In addition, use
in a well-ventilated room (open doors and windows). Provide
goggles during the experiment to prevent eye irritation. Warn
participants to avoid direct inhalation of the fumes.
3. Heating pad
in the fuming
chamber
base
The heating pad carries a risk of heat and cold burns.
Participants should not touch the pad, especially when it is
heating up. Let it cool down completely before moving the
metal glue disk after the experiment. All equipment should be
used under controlled conditions. All mains leads should be
taped down or sited out of reach.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
What to prepare before your club session
This activity works best when the instructions are followed closely. (Look at the
PowerPoint presentation that is specifically designed to introduce the activity to
your students.)
Wear gloves and goggles at all times during the activity!
1. Place the metal disc on the heating pad
in the base of the fuming chamber.
2. The group leader should add a tiny
amount of superglue on top of the
metal disc.
3. Attach the crocodile clip to the grille
and place it over the glue disk.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
How to run the activity
5. Place the cup over the base plate.
Make sure that the fuming chamber is
sealed (just pressing down is enough).
6. Set the power supply to 6 V.
7. Connect your fuming chamber to the
power supply and turn the power on.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
4. Clip the piece of evidence with the
crocodile clip.
9. Remove the piece of evidence from
the fuming chamber and analyse the
fingerprint, e.g. with a magnifying
glass. Compare it to the four suspects’
fingerprints. Can you tell ‘whodunnit’?
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
8. Stop the experiment after about
2 minutes by switching off the power.
Wait for another 30 seconds before
you finally take the cup off in a fume
cupboard (making sure you are still
wearing your goggles).
• Make sure that you stop the experiment as soon as you can see that something
white has developed on the plastic slide. If the experiment runs for too long, too
much superglue vapour will stick to the piece of evidence, which means that the
fingerprint will no longer be recognisable.
• After switching off the power, do not lift the cup up before you have put it in a
fume cupboard. Wait for at least 30 seconds before you lift the cup up.
• Humidity is crucial for the success of this activity; when it is too low there is a
risk of the experiment failing. Therefore, if you notice that the superglue does not
evaporate, place another metal disc with a large drop of water next to the grille.
Ideas for discussion with students
IDEAS!
Discussion is important as it allows students to explore and
discuss issues as well as listening to, respecting and challenging
other viewpoints in a safe and supportive environment. It can
be further used to engage students with applications and implications of
science by exploring how creative applications of scientific ideas can bring about
technological developments and consequent changes in the way people think and
behave. Discussion can also engage your students to develop communication skills
by using appropriate methods to communicate scientific information and contributing
to presentations and discussions about scientific issues. Last but not least,
discussion allows your students to express informed opinions on scientific issues and
technological developments.
Some questions that came up from club students and leaders when testing the
prototypes are:
• What fingerprint patterns are most common in your club?
• Do all your fingers and thumbs have the same pattern?
• Even when you have the same pattern as your friend, how can you distinguish each
other’s fingerprints?
• What is a fingerprint made out of?
• How can I touch something with my bare hands without leaving a fingerprint behind?
• How can you make a fingerprint visible with superglue?
• Why is humidity important?
• What other methods can you use to investigate fingerprints?
• How can somebody fake your fingerprint?
• Why does superglue stick to your fingers?
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
Top tips
Activity 1:
Fuming fingerprints
The science behind the activity
Image: HOSB
a. Superglue
Superglue usually consists of ethyl cyanoacrylate that hardens in contact with water.
Superglue does not stick to the inside of the tube as there is no water present. In
contrast, water exists in the air in the form of microscopic droplets (moisture) and
that’s why superglue hardens as soon as it is exposed to the air. If you want superglue
to harden even more quickly you only have to breathe on it as the moisture in your
breath will increase the amount of water in contact with the glue.
Superglue has also become an extremely useful forensic tool to make latent
fingerprints visible on non-porous surfaces such as glass or plastic. Latent
fingerprints are prints that can’t be seen with the naked eye. Ethyl cyanoacrylate can
react with various constituents in the fingerprint including water to become a visible
white layer when warmed up under controlled conditions of humidity. This involves a
special chemical reaction called polymerisation, in which monomer molecules stick
together and form three-dimensional chains. As the product of this chemical reaction
is a white print, the superglue technique allows scientists to recognise developed
fingerprints with the naked eye on most surfaces that do not have a white background.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
b. The role of heat in the superglue
fuming technique
There are several ways in which
superglue can be used to develop
fingerprints on surfaces. The
best way is to bring all moveable
items back to a laboratory and
to treat them in a humiditycontrolled cabinet, which
uses a built-in heater stage to
evaporate liquid superglue from
an aluminium foil pot.
In this activity, the small white square
set into the orange base represents
the heater stage in the professional
chamber. This square is a Peltier cell,
which consists of a number of junctions
made from semiconducting materials
sandwiched between two ceramic plates.
When the plate is attached to the power
supply an electrical current passes
through it, caused by a complex process.
As a result of this current flow, one side
of the Peltier cell gets hotter and the
other side gets colder. This temperature
difference within the plate allows it to
act as a ‘heat pump’, hence its use in
everyday applications such as portable
cool boxes.
Steve Bleay, Home Office Scientific
Development Branch, 2009
Image: HOSB
Only the hot side of the Peltier plate
plays an important role in the fuming
fingerprints activity. Its purpose is to
warm up the superglue, whereas the
cold side of the Peltier plate contributes
nothing to the activity and is hidden inside
the base. To protect the Peltier plate
from any direct contact with superglue,
you and your students need to place the
metal disc on top of it, and then put a tiny
drop of superglue on top of the metal
disc. Real scientists use aluminium foil,
but the disc used in this activity is made
of steel. Despite this difference, both
metals fulfil the requirement for the
fuming chambers: they conduct heat
so that the superglue can evaporate.
Other materials such as plastic, glass
or wood would not be suitable as they
are naturally poor conductors.
This is a fuming chamber that scientists at the
Home Office Scientific Branch use to develop
latent fingerprints with superglue fumes.
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Club leader notes crime lab
Loops
Activity 1:
Fuming fingerprints
c. What makes our fingerprints unique?
Whorls
Arches
There are only three potential types of fingerprints. In 1685, Marcello Malphigi
recognised two of them: ‘loops’ and ‘whorls’. The third pattern, the ‘arch’, was
identified by Sir Francis Galton more than 200 years later, in 1892. Loops are the most
common; 60% of people have this type, 35% have whorls and 5% have arch shapes.
Although everyone has one of these general types, each person’s fingerprints are still
unique as they consist of different numbers of these patterns. The reason everyone’s
ridge patterns are different is because of something that happens in the womb. As
the foetus develops, it stretches and bends its fingers, causing ridges to form or
stop forming as the tension of the skin varies. Because every foetus does this in a
different way, every fingerprint develops differently. Even identical twins have different
fingerprints. The chance that your fingerprint will match someone else’s exactly is
thought to be only 1 in 64 billion. However, when you check fingerprints you have to
make sure to record which finger you take, as the patterns even vary from finger to
finger on any one individual.
In contrast to our appearance, fingerprints remain unchanged throughout life.
The skin is able to repair itself and heal wounds. That’s why the fingerprints may
disappear for a while if the pads of your fingers are burned or shaved off, but they
reappear again at some point. This unique, everlasting characteristic is the reason
why fingerprints are taken for identity. The only exception is when there is severe
damage to the deeper layers of the skin in your fingertips. This can lead to scars that
may stay for ever. Obviously, those scars would, on the one hand, make it difficult for
any examiners to identify the fingerprints, but on the other hand any suspect who has
removed all of his or her fingerprints would arouse suspicion.
As fingerprints are unique, they can be also used for other purposes, such as:
• To prevent forged signatures
• To identify accident victims
• To verify job applicants
• To provide identification on new UK ID cards and biometric passports
• To provide personalised access to everything from cashpoint machines
to computer networks.
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Club leader notes crime lab
a. Different types of fingerprints
1. Patent prints
We leave fingerprints almost everywhere but in different forms. When your fingertip
touches a dirty surface such as a dusty window frame, some of the dirt will be
removed by your skin, leaving behind a negative print called a ‘patent print’. This
can happen in reverse too: if you touch a very clean surface with a finger that is
contaminated with any trace of something such as blood, ink or paint, you make a
visible, positive patent print. You can also leave more permanent patent prints on the
surface of some materials such as copper. The acids in the sweat on your fingers can
etch the surface of these materials and make indelible prints.
2. Plastic prints
The ridges of your fingerprints can make marks in a soft surface to create a threedimensional print. This can happen in substances such as wax, putty, clay, chalk, soap,
cold butter or even dust.
3. Latent prints
Latent prints occur when sweat, oil and other substances on the skin leave the ridge
structure of the fingerprints on objects such as glass or plastic. These prints can’t be
seen with the naked eye, but they can be made visible with special processing, such as
superglue fuming, or under certain types of light.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
Links to everyday life
Activity 1:
Fuming fingerprints
b. Superglue technique
Image: HOSB
You can see patent and plastic
fingerprints with your naked eye, but not
latent fingerprints. Therefore, you have
to develop them with special methods
first before you can analyse them further.
One of those methods is the superglue
technique, discovered independently in
three different countries in the 1970s.
Specialists in Canada and Japan identified
the process as part of speculative studies
into fuming processes that could develop
fingerprints, but Laurie Wood, working
for Northamptonshire Police, discovered
the process in the UK in a more accidental
fashion. He observed that fumes from
the superglue he was using to make
repairs were developing fingerprints on
adjacent items and brought this to the
attention of his employers and forensic
research organisations.
If developing fingerprints in a fuming chamber
isn’t possible, investigators can treat entire
rooms by using mobile equipment that
includes portable heated stages for pots
of superglue.
Even today, specialists are still trying to improve techniques of fingerprint
development. Steve Bleay is a Higher Scientific Officer at the Home Office Scientific
Development Branch, working in the Fingerprint and Footwear Forensics Group.
His group are responsible for providing best-practice advice to police forces on
the development and imaging of fingerprints and footwear marks. They do this by
experimenting with new and unusual development and imaging techniques and
carrying out comparisons with existing methods. If developing fingerprints in a fuming
chamber is not possible, real crime-scene investigators have another way of making
them visible. They can treat entire rooms with mobile equipment consisting of a
humidifier and portable heated stages for pots of superglue. Do not try to reproduce
this in your classroom!
When real scientists who have used the fuming technique still have poorly visible
prints they can enhance them further by dipping them into a bath containing a
fluorescent dye. The dye is absorbed into the polycyanoacrylate fibres of the white
fingerprint. This technique makes the print glow under a laser or ultraviolet light and
has the added advantage of making the print more persistent and stable.
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Club leader notes crime lab
You might wonder why the police ‘dust’ some prints but use fuming for others.
Which method investigators use depends on the surface beneath the print. When
investigators have to develop latent fingerprints on more porous surfaces, special
chemicals such as ethyl cyanoacrylate in superglue (see page 11) are more suitable
than powders. However, real scientists can use other chemicals to develop latent
fingerprints as well.
When heated, solid iodine reacts with oils in latent fingerprints to form a brownish
print. As the developed print fades quickly, scientists have to take photographs
immediately or fix it with other techniques. Another chemical that reacts with
the oils of latent prints is ninhydrin (triketo hydrindene hydrate). The product of
this reaction is purple-blue. However, the development of the print through this
technique can take several hours. Last but not least, silver nitrate powder can be
used to develop a latent print. It reacts with the salt in the print (the chloride ions)
to form a colourless print (silver chloride crystals), which becomes black or
reddish-brown when exposed to ultraviolet light.
If the latent fingerprint is left on a harder surface, special powders are typically
used to develop it. These powders make prints visible by adhering to the moisture
and oils they contain. Specialists have to choose between different powders
depending on what colour and type gives the greatest degree of contrast with the
background surface. Grey powder, made from aluminium or titanium, is the most
common. But there are also other specialised powders such as black powder, made
from carbon black or charcoal, and fluorescent powder, which makes the print glow
under special light. After the powdering process is complete, the specialists then
either photograph the print or gently lay the sticky surface of a strip of transparent
tape over the print and lift it.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
c. Further techniques for latent fingerprint development
Who am I? gallery: Find out more about what makes you unique, but also what you
have in common with other humans and species.
Links to the National Curriculum and Scottish Curriculum
The activities in the box are designed to enrich and extend your classroom activities,
but they also have some strong links to the UK and Scottish curricula if you wish to
use them. We have listed the ones that we feel are most relevant, but you may find
others, particularly if they relate to other classroom activities that your students are
familiar with. Forensic science also appears as a theme in general programmes of
study, and this activity can extend this theme.
UK National Curriculum KS3
Science
1.1. Scientific thinking
a. Using scientific ideas and models to explain phenomena and developing them
creatively to generate and test theories.
b. Critically analysing and evaluating evidence from observations and experiments.
1.2. Applications and implications of science
a. Exploring how the creative application of scientific ideas can bring about
technological developments and consequent changes in the way people think
and behave.
1.4. Collaboration
a. Sharing developments and common understanding across disciplines
and boundaries.
2.1. Practical and enquiry skills
Pupils should be able to:
b. assess risk and work safely in the laboratory, field and workplace.
c. plan and carry out practical and investigative activities, both individually
and in groups.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
Links to the Science Museum
Pupils should be able to:
b. evaluate scientific evidence and working methods.
4. Curriculum opportunities
Pupils should be able to:
a. research, experiment, discuss and develop arguments.
b. pursue an independent enquiry into an aspect of science of personal interest.
c. use real-life examples as a basis for finding out about science.
Scottish Curriculum for Excellence
Materials
Properties and uses of substances
SCN 2-15a
By contributing to investigations into familiar changes in substances to produce other
substances, I can describe how their characteristics have changed.
Materials
Chemical changes
SCN 2-19a
I have collaborated in activities which safely demonstrate simple chemical reactions
using everyday chemicals. I can show an appreciation of a chemical reaction as being
a change in which different materials are made.
Topical science
SCN 4-20a
I have researched new developments in science and can explain how their current or
future applications might impact on modern life.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
2.2. Critical understanding of evidence
a. Detectives’ dilemma
Give your students different materials on which they may find fingerprints, e.g.
transparent plastic packaging, white plastic or colourful paper. Not only will your
students have to identify the fingerprints after the development process, but they also
have to choose which method is best for each surface. They can choose between the
superglue technique (if the sample will fit into the fuming chamber) and the powder
technique. For the powder technique you will need to provide options to provide
contrast on different backgrounds, e.g. using cornflour or talcum powder to contrast
with dark surfaces, and cocoa powder for light surfaces (check that your students
don’t have allergies to these foodstuffs and ensure they protect their eyes and don’t
breathe in the powder).
b. Making another polymer: slime
What you need (per group):
• 2 x disposable plastic cups
• Multipurpose PVA glue
• Water
• Borax
• Spatulas/stirrers
• Food colouring (optional)
• Zip-seal plastic bag for storage
1. Pour about a centimetre of PVA glue into a disposable plastic cup.
2. Pour the same amount of water on top of the glue.
3. Use one of the spatulas/stirrers to mix up the glue and water.
4. Add food colouring if desired.
5. In a separate cup mix about 5 ml of borax into 20 ml of water (you don’t have to be
totally accurate).
6. Mix the borax and water well. Hint: If you use cold water the borax will not dissolve,
but as long as you mix it up well and make sure you pour both water and borax
particles into your slime mixture it will be fine.
7. Add about 5 ml of the borax solution/mixture to the water–glue mixture and stir it
until you get a sticky substance – your slime!
8. You can take the slime out of the cup and squeeze it. The more you stretch and play
with it the more rubbery it becomes.
Hint: The slime will stay fresh in a zippered plastic bag in the refrigerator for quite a
while, but it will dry out if left out overnight.
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Club leader notes crime lab
Activity 1:
Fuming fingerprints
Extension ideas
Swipe card
Aim of this activity
Materials
A
This box provides enough materials for
5 groups, each consisting of 3–4 students.
Each group will have the following materials:
A
1 x pot of magnetic powder
B
1 x brush
C
x magnetic-strip cards (which you
4
will have coded in preparation)
B
We have also provided the following
materials for you to give to the groups
and for preparation:
D
E
C
D
1
x pot containing 5 x programming tools
and magnets (each group requires 1 tool
and 2 small magnets)
1 x wiping magnet
Caution – these are powerful magnets.
Please read the health and safety information
on page 22.
You will need to provide:
1 x roll of sticky tape per group
1 x A4 sheet of white paper per student
(optional)
1 x coding system sheet per group (page 25)
Information about the suspects for every
group (see pages 63–67, 73–78)
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Club leader notes crime lab
E
Activity 2:
Swipe card
In this activity your students will crack a hidden code on magnetic-strip cards with
magnetic powder to make the code visible and use a coding system to decipher the
information. This activity not only allows your students to learn where they can find
hidden information in everyday life, e.g. on train tickets or credit cards, but also to use
mathematical skills to crack a code.
What to prepare before your club session
For this activity you must code the swipe cards in advance. To code all the cards in this
box you should allow approximately 30 minutes.
1. Every student group will get one swipe card taken from each ‘suspect’. As the cards all
look the same we recommend that you write the references A, B, C and D on the back
of them so that your students don’t mix them up. Alternatively, you can label plastic
bags with A, B, C and D and put the cards without any numbers in the bags.
• First, use the strong wiping magnet to wipe over every magnetic stripe. This will
ensure you start with all surfaces clear.
• Then, divide your cards up into four different groups. The coding system is the same
for all four suspects, but the time information on each is different. The code is made
using a combination of the two magnets on the programming tool to produce large
circles, small circles or lines (using the flat end of the tool, which has a magnet
attached). When the shape changes this shows that you are moving to a different piece
of information, e.g. from hours to minutes.
More information about how to code the different cards is given on pages 59 and 72.
We have provided you with two different versions of our crime story: version 1 allows
you to use all three activities from the box as one longer project (so your students need
to do all three activities to find out who committed the crime) and version 2 allows you
to deliver each activity as a stand-alone session (so students can identify the thief after
any one session). This also means that you will need to code the swipe cards slightly
differently depending on which version you choose (see pages 58 and 69).
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Club leader notes crime lab
Activity 2:
Swipe card
2.As there are four different suspects you must not only hand out the cards taken from
the different suspects separately but also code them differently. Instructions for the
codes are as follows:
Health and safety information for your risk assessment
From our extensive testing in clubs around the UK, we recommend the following
elements are considered in your risk assessment for this activity. However, you
know the needs of your group and the environment you are working in, so we would
strongly advise you to consider if any additional elements apply in your particular
circumstances, before you run this activity. If in doubt contact CLEAPSS
(cleapss.org.uk) for further information. All resources should only be used under
adult supervision.
Information for your risk assessment
1.Strong
magnets
All magnets can affect electronic and magnetic equipment, e.g.
credit cards, swipe cards, magnetic keys. Strong magnets may
affect pacemakers, hearing aids and other medical devices.
If two of the smaller magnets are swallowed it can be
particularly dangerous and could cause death.
Never put strong magnets in your pocket as two magnets in
close proximity can jump together and pinch skin or shatter.
2.Magnetic
powder
(very fine
iron powder)
Powder should not be ingested or inhaled. Powder should also
be kept away from your eyes.
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Club leader notes crime lab
Activity 2:
Swipe card
Activity element
How to run the activity
This activity works best when the instructions are followed closely. (Look at the
PowerPoint presentation that is specifically designed to introduce the activity to
your students.)
2. Tap the edge of the card on the table so
that there is only a thin layer of powder
left on the magnetic strip (if students
do this onto a sheet of paper it makes it
easier to clear up afterwards!).
3. Use a strip of sticky tape to lift the
magnetic pattern.
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Club leader notes crime lab
Activity 2:
Swipe card
1. Load the brush with a small amount of
magnetic powder and brush it directly
onto the magnetic strip on the card
(which you have coded).
4. S
tick the tape onto white paper or your
student logbook so you are able to
see the code. Students in one group
can repeat this process so that every
student gets to stick one tape in his or
her logbook (for example).
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Club leader notes crime lab
Activity 2:
Swipe card
5. Crack the code using the coding
system sheet. Find out who is the
potential thief by comparing the
time on the swipe card with the
suspects’ statements.
2. Next, count the number of small circles to work out the hour.
3. Finally, count the number of large circles. Each one is worth
15 minutes, so add them up to work out the time. If there are
no large circles then the time is exactly on the hour (i.e. no
minutes past).
4. Read the suspect statements to see who is telling the truth.
3. Finally, count the number of large circles. Each one is worth
15 minutes, so add them up to work out the time. If there are
no large circles then the time is exactly on the hour (i.e. no
minutes past).
4. Read the suspect statements to see who is telling the truth.
= 4.30pm
(15 minutes each)
2. Next, count the number of small circles to work out the hour.
so...
(1 hour each)
= pm
= minutes
1. Starting from the left, work out if it is am (after midnight but
before noon) or pm (after noon but before midnight).
= 4.30pm
(15 minutes each)
= hours
= am
1. Starting from the left, work out if it is am (after midnight but
before noon) or pm (after noon but before midnight).
so...
(1 hour each)
= pm
= minutes
You should be able to see a pattern of lines, large circles and
small circles which will tell you the time when the suspect last
used the card.
You should be able to see a pattern of lines, large circles and
small circles which will tell you the time when the suspect last
used the card.
= hours
Taking each card in turn, brush magnetic powder onto the
magnetic strip, tap off the excess, then lift the code using a strip
of tape. Stick it onto white paper to make the code easier to read.
Taking each card in turn, brush magnetic powder onto the
magnetic strip, tap off the excess, then lift the code using a strip
of tape. Stick it onto white paper to make the code easier to read.
= am
Coding system sheet
Coding system sheet
Top tips
• Ask your students to fold then unfold the white paper before tapping the magnetic
powder onto it. This makes it easier to pour the powder back into the pot.
• Your students won’t be able to crack the codes when the coding system isn’t clear
to them. So make sure that you fully understand it, and then discuss it in detail
with the students, e.g. on a whiteboard.
• Your students could use clear sticky tape to transfer the code from the card or
paper to their student logbooks.
• You can use the information about the suspects in this activity alone or in
conjunction with the other activities in this box, to provide more evidence to
support students’ theories.
• Ask your students to decode each card more than once to ensure accurate
results and develop their technique.
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Club leader notes crime lab
Activity 2:
Swipe card
• If you have additional brushes available you can ask the student groups to divide
the work. For example, one student per group could investigate each of the four
suspects. They can discuss within their group afterwards to decide which person
is most likely to have attempted the robbery.
Ideas for discussion with students
IDEAS!
Some questions that came up from club students and leaders when testing the
prototypes with them are:
• How do machines code the cards when you use them, e.g. travel cards and
cash cards?
• What different coding systems exist?
• Who might use the information?
• Is anyone able to track me by examining how and when I use my cards?
• How much personal information (such as s biometric data) should a magnetic card
hold? What do you think from an ethical point of view?
• How many functions should your ideal card have in the future? Just bank details, or
everything so you only have to carry one card?
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Club leader notes crime lab
Activity 2:
Swipe card
Discussion is important as it allows students to explore and
discuss issues as well as listening to, respecting and challenging
other viewpoints in a safe and supportive environment. It can
be further used to engage students with applications and implications of
science by exploring how creative application of scientific ideas can bring about
technological developments and consequent changes in the way people think and
behave. Discussion can also engage your students to develop communication skills
by using appropriate methods to communicate scientific information and contributing
to presentations and discussions about scientific issues. Last but not least,
discussion allows your students to express informed opinions on scientific issues and
technological developments.
The science behind the activity
a. Magnetism
When you swipe the strong magnet over the entire strip in one go, from one side
to the other, the iron particles in the magnetic strip create a permanent magnetic
field that is oriented in one direction. When you touch only certain places on the
magnetic strip with the programming magnets, the iron particles in these places are
reoriented, creating a permanent magnetic field in a different direction to the rest of
the strip. This can become visible when you put the magnetic powder over the coded
magnetic-strip cards.
b. Magnetic powder
The magnetic powder included in this activity is just a very fine
iron powder, much finer than iron filings. When you brush it
over the encoded magnetic strips it becomes magnetic and gets
attracted by the magnetic fields you have set up on the cards’
magnetic strips.
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Activity 2:
Swipe card
As you know, a magnet has two poles, south and north.
When two like poles face each other, e.g. north to north, the
two magnets are repelled. When two opposite poles face
each other, i.e. north to south, they attract. Some metals
are capable of being strongly magnetised, a property called
ferromagnetism. However, only iron, nickel and cobalt can be magnetised by a magnet
at room temperature. That’s why the magnetic strip on the cards in this activity is
made of a flexible polymer that is loaded with iron.
Links to everyday life
a. Magnetic-strip cards
Activity 2:
Swipe card
The magnetic strip on many cards such as credit cards, identity cards or travel tickets
is able to store data in the form of a code. This is possible because it contains tiny
iron-based magnetic particles that can be oriented in a particular way using a magnet
in the card machines.
In newer-generation cards referred to as ‘smart cards’ there is also an integrated
circuit chip which can store data. The chip may either physically connect to a sensor in
the card reader or use radio-frequency identification (RFID) so it can be read without
physical contact. In the latter case, holding the card close to the reader is enough to
complete the transaction. Examples of smart-card technology in everyday life include
keyless car ignition and London’s ‘Oyster’ travel cards.
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Club leader notes crime lab
b. The history of bar codes
Activity 2:
Swipe card
Another coding system that we use in our everyday life is the bar code. Did you know
that the first time a bar-coded product was scanned was at a supermarket in Ohio,
USA on 26 June 1974? It was a single pack of Wrigley’s Juicy Fruit chewing gum,
which is now on display at the Smithsonian Institution’s National Museum of American
History in Washington DC.
The concept of bar codes was invented by N Joseph Woodland. He came up with
the initial idea in the 1940s, but the technology for scanning them didn’t become
commercially viable until the 1970s. Woodland was finally recognised for his invention
when he received the United States National Medal of Technology in 1992.
Since bar codes were first used they have been adapted for more and more
applications. For instance, researchers now use tiny bar codes on bees to track the
insects’ mating habits and hospital patients wear bar-code ID bracelets to ensure
there are no mix-ups with their records.
As technology progresses there is a need to pack more and more information onto
cards. And because this requires more space for the code than current cards can
provide, new types of bar codes have to be invented. The technology began with
simple black-and-white line codes, and was followed by layered or ‘matrix’ codes in
the 1990s. Now mobile phones are able to read a variety of specially designed mobile
bar codes. This has only been made possible by recent advances in bar-code reader
technology that has allowed cameras in mobile phones to act as code readers.
The history of bar codes is a very good example of how people from the various fields
of science, engineering, technology, mathematics, retail and design need to work
together to introduce and refine a new and successful technology.
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Club leader notes crime lab
Links to the Science Museum
•C
omputing gallery: Have a look at what we believe is the last surviving valve-based
computer, Pegasus. Learn how this computer was able to decode information from
a punched paper tape and transform it into text. You and your students can get
further information about the history of computing in this gallery.
sciencemuseum.org.uk/objects/radio_communication/1980-1200
Links to the National Curriculum and Scottish Curriculum
The activities in the box are designed to enrich and extend your classroom activities,
but they also have some strong links to the UK and Scottish curricula if you wish to
use them. We have listed the ones that we feel are most relevant, but you may find
others, particularly if they relate to other classroom activities that your students are
familiar with.
UK National Curriculum KS3
Design and Technology
1.1. Designing and making
c. Understanding that products and systems have an impact on quality of life.
d. Exploring how products have been designed and made in the past, how they are
currently designed and made, and how they may develop in the future.
Mathematics
1.3. Application and implication of mathematics
b. Understanding that mathematics is used as a tool in a wide range of contexts.
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Activity 2:
Swipe card
•T
elecommunications gallery: Find out what the Cooke and Wheatstone doubleneedle telegraph from 1844 has to do with coding systems, the way our mobile
phones work and even with trapping a murderer. Can you also find the three-ring
Enigma cipher machine? You can learn about its historical impact on the cracking
of codes at:
2.1. Representing
Pupils should be able to:
a. identify the mathematical aspects of a situation or problem.
b. choose between representations.
c. simplify the situation or problem in order to represent it mathematically, using
appropriate variables, symbols, diagrams and models.
2.2. Analysing
Use mathematical reasoning
Pupils should be able to:
d. identify and classify patterns.
Use appropriate mathematical procedures
Pupils should be able to:
o. record methods, solutions and conclusions.
Scottish Curriculum for Excellence
Technology
Technological developments in society
TCH 3-01a
From my studies of technologies in the world around me, I can begin to understand
the relationship between key scientific principles and technological developments.
Mathematics
Number, money and measure
Patterns and relationships
MTH 1-13b
Through exploring number patterns, I can recognise and continue simple number
sequences and can explain the rule I have applied.
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Activity 2:
Swipe card
d. select mathematical information, methods and tools to use.
MTH 3-13a
Having explored number sequences, I can establish the set of numbers generated by
a given rule and determine a rule for a given sequence, expressing it using
appropriate notation.
MTH 4-13a
Information handling
Data and analysis
MNU 3-20a
I can work collaboratively, making appropriate use of technology, to source
information presented in a range of ways, interpret what it conveys and discuss
whether I believe the information to be robust, vague or misleading.
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Activity 2:
Swipe card
Having explored how real-life situations can be modelled by number patterns, I can
establish a number sequence to represent a physical or pictorial pattern, determine
a general formula to describe the sequence, then use it to make evaluations and
solve related problems.
Extension ideas
a. Create your own coding system
Students can come up with their own coding system:
1. Invent a coding system to represent time, letters or numbers that will fit on the
magnetic strip and consists of one, two or all of the shapes of magnets from the
programming toolkit.
2. Choose a time you want to code on your card.
4. Code your card’s strip with your chosen time using magnets from the programming
toolkit. As soon as you have finished writing your code, put these magnets away too,
as they can also wipe off your code.
5. Record your coding system (but don’t give away the answer) as a code-breaking
‘key’, and give this and the coded card to one of your fellow students. See whether
he or she can crack your code on the card.
b. Let the compass tell the time
For this activity you will need some canisters (e.g. camera film canisters), magnets
that will fit in the canisters and at least one compass.
1. Give your students one of the coding systems (see below). The smaller the number
of containers your students use, the more challenging it will be for them to code a
time. However, there is only one way to represent any given time when using only
five containers.
2.Ask them to choose a time. This must be their secret, so they shouldn’t say it out loud.
3. Your students have to find out which canister they need to fill with magnetic items,
and which they leave empty to represent their chosen time. The canisters should
not be picked up – students may only decode the time from the reaction of the
compass, not from whether an object rattles inside the container.
4. Fellow students should be able to decipher their classmates’ times by swiping the
containers with the compass in the proper order and using the coding system to
identify the time.
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Activity 2:
Swipe card
3. Swipe the magnetic strip with the large wiping magnet to erase any existing codes.
Then put the wiping magnet away immediately as it will destroy the new codes you
are trying to put on the card.
Tip: Your students should not touch the canisters, as they will be able to tell from
their weights which ones contain magnets. They must only use the compass. If you
have suitable materials you can ask your students to put non-magnetic items such
as marbles in the canisters without magnets. Or you can even challenge them by
providing them with a range of materials and asking them to find out which ones are
magnetic and which ones are not.
Here’s another that uses
only six containers:
Here’s a five-container
coding system:
Container Magnet value
Container Magnet value
Container Magnet value
1st
4 hours
1st
10 hours
2nd
4 hours
2nd
10 hours
1st
Magnet pm;
no magnet am
3rd 4 hours
3rd 5 hours
2nd
8 hours
4th
4 hours
4th
2 hours
3rd 4 hours
5th 4 hours
5th 1 hour
4th
2 hours
6th 2 hours
6th 1 hour
5th 1 hour
7th
1 hour
8th
1 hour
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Club leader notes crime lab
Activity 2:
Swipe card
Here’s a coding system that
uses eight containers:
c. Follow the bar-code trail
Mobile-phone games can promote students’ involvement in different tasks such as
investigation, content generation, collaboration, problem-solving and navigating their
way round trails. All of these activities make use of a much-loved gadget and can be
further seen as important components that support a wide variety of cognitive and
social skills.
2. Ask students to choose an item in your classroom that they want to create a code
for. This could be their free choice or could follow a theme you have selected such
as ‘fluorescence’, ‘magnets’ or ‘polymers’. Using the link above, get the students
to create a bar code for their object, which they can then print out and attach to it.
The message can consist of no more then 60 characters, so this is a great way of
ensuring students carefully consider the exact wording of their message.
3. When all the codes are ready and attached to objects around the classroom,
students can go on a bar-code hunt to find and scan all the various codes to
discover the secret messages that have been linked to them. The message will be
displayed on their phones when they scan the code with the mobile.
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Activity 2:
Swipe card
1. For example, use the bar-code creator at http://mobilecodes.nokia.com/index.htm
to design codes. Students will receive a text with information when they scan the
codes using a mobile phone, here a Nokia phone. Most 3G phones will either have
this feature installed or can download it. The link includes a list of phone makes
and models that can be used for this activity. Other websites that provide bar-code
creators and work for different mobile phones are e.g. http://reader.kaywa.com and
i-nigma.com/Create.asp.
Casting
Aim of this activity
In this activity students will make impressions of bite marks in apples and compare
them with bite marks on Plastazote sheet. The activity allows students to develop
their observational skills so they recognise and identify bite marks. Forensic
dentists can use dental records to identify people because your teeth are as
unique as your fingerprints.
Materials
This box provides enough materials for
your entire club. Give every student the
following materials:
1 x A7 piece of Plastazote foam
B
4 x spoons of dental alginate
A
B
You will need to provide for each student:
Water
1 x 250 ml container per student
1 x stirrer per student
1 x apple per student (or cheese – see
health and safety instructions on page 38)
For the crime story you will also have
to provide:
Information about the suspects for every
group (see page 68 or 80)
4 x Plastazote sheets with the suspects’
bite marks
1 x bitten apple
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Activity 3:
Casting
A
What to prepare before your club session
1. Before the session, ask your students whether any of them have an allergic
reaction to apples, and whether they wear braces/dental prosthetics.
2. Bring enough apples to the club session so that there is one for each student
attending, and provide cheese for those students who can’t use apples.
After your students have practised their observation skills you can give them a piece
of evidence (apple with bite mark) to solve the crime from our museum story. We
have provided you with two different versions of our crime story: version 1 allows you
to use all three activities from the box as one longer project (so your students need
to do all three activities to find out who committed the crime) and version 2 allows
you to deliver each activity as a stand-alone session (so your students can identify
the thief after any one session). Preparation for this activity is the same for both
versions – information about how to prepare the piece of evidence for the crime story
is on pages 60 and 79.
From our extensive testing in clubs around the UK, we recommend the following
elements are considered in your risk assessment for this activity. However, you
know the needs of your group and the environment you are working in, so we would
strongly advise you to consider if any additional elements apply in your particular
circumstances, before you run this activity. If in doubt contact CLEAPSS
(cleapss.org.uk) for further information. All resources should only be used under
adult supervision.
Activity element
Information for your risk assessment
1. Alginate
powder
Don’t eat or inhale the powder.
2. Apples
Check that none of the participants have an allergy to apples
before the activity. Provide alternatives such as cheese if
necessary. We also recommend that any students wearing
fixed braces or with dental prosthetics do not use apples.
Don’t tip the powder down the sink as it could block your drain
when mixed with water. You can put the powder in the bin.
As you are encouraging your students to take a large bite,
ensure that they chew well before swallowing to avoid any
risk of choking.
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Club leader notes crime lab
Activity 3:
Casting
Health and safety information for your risk assessment
How to run the activity
This activity works best when the instructions are followed closely. (Look at the
PowerPoint presentation that is specifically designed to introduce the activity to
your students.)
Getting a record of students’ teeth
1. Fold the Plastazote sheet in half
and bite down hard, with as big a
bite as possible.
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Club leader notes crime lab
Activity 3:
Casting
2. It is important that students put their
name on the back of the Plastazote
sheet so they can recognise their
own bite mark later.
Casting a bite mark
1. Take as big a bite as possible out
of an apple.*
2. Then take four big spoons of
alginate powder.
Activity 3:
Casting
3. Mix the powder with a little water.
Hint: Students can always add more
water if necessary, but if they use too
much at the beginning the impression
will not work very well.
*Provide cheese for those students who have an allergic reaction to apples.
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Club leader notes crime lab
4. Students should stir until the
paste is purple.
6. As soon as it goes white, remove
the impression.
Hint: Students should also put their
name on their cast.
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Club leader notes crime lab
Activity 3:
Casting
5. Then immediately pour the purple
paste onto their apple bite as it takes
less than a minute to dry.
Comparing impressions and recording
1. When their impressions are dry,
students can compare their bite
impression with the one on the
Plastazote sheet.
Solving the crime
When they have practised their casting skills and learned what to look out for in
identifying a suspect, give the students the four Plastazote sheets with the bite
marks taken from the ‘suspects’, plus the apple from the ‘crime scene’. Can they
find out ‘whodunnit’?
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Club leader notes crime lab
Activity 3:
Casting
2. Now students should swap their
impressions and Plastazote sheets
with each other and see if they can
match the right impression to the
right bite mark.
Top tips
•Ask your students to label the back of their cast and their Plastazote sheet with
the bite mark impression, so that you can check whether they matched the
correct cast with the correct bite mark. Make sure that they don’t look at the
answer on the back!
• Stress to your students that they should make the biggest bite possible in
both Plastazote and apple. This increases the common characteristics in
both substances.
• Use cold water for this activity. This gives your students a minute to cast their
apple bite, whereas the powder dries within 30 seconds when mixed with
warm water.
• Polystyrene tiles or plates are a good substitute for the Plastazote sheets.
Students can also try biting this material with different pressures to see how
this affects the evidence they leave behind.
• Your students can get a ‘positive’ from their impression when they cast it, e.g.
using alginate powder or plaster of Paris.
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Club leader notes crime lab
Activity 3:
Casting
• Split your students into groups of three and ask them to match three casts with
bite marks from another group. This provides them with enough opportunity to
use their observational skills without overwhelming them with too many
different casts to match up.
Ideas for discussion with students
IDEAS!
Discussion is important as it allows students to explore and
discuss issues as well as listening to, respecting and challenging
other viewpoints in a safe and supportive environment. It can be
further used to engage students with applications and implications of
science by exploring how creative application of scientific ideas can
bring about technological developments and consequent changes in the
way people think and behave. Discussion can also engage your students
to develop communication skills by using appropriate methods to
communicate scientific information and contributing to presentations
and discussions about scientific issues. Last but not least, discussion
allows your students to express informed opinions on scientific issues
and technological developments.
Some questions that came up from club students and leaders when
testing the prototypes with them are:
• What other materials can you leave a bite mark on?
• What other materials change phase like this casting powder?
• Does alginate powder mixed with water change its colour from liquid
to solid because this is a chemical or physical reaction?
• Is it a reversible or non-reversible change?
• Who may use dental records? And what may these people use
them for?
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Club leader notes crime lab
Activity 3:
Casting
• What is the casting powder used for?
The science behind the activity
a. Features of chromatic alginate powder
Alginate powder is made from a derivative of seaweed and
other chemical compounds and has the ability to absorb water
quickly. Alginate powder reacts with water to form a mixture
that immediately sets and becomes a flexible, rubbery mass.
Because the alginate–water mix changes colour as it changes
phase from liquid to solid, alginate powder is sometimes
called ‘chromatic alginate’. The powder is able to chemically
change colour because it has a minute trace of hydrochromic
dye added to it for this purpose.
b. Bite marks can help solve a crime
Such bite-mark analysis is based on two factors:
1. The bite we produce is unique and depends on our individual dental characteristics.
2. This uniqueness is transferred and recorded in the substance where the bite mark
is left.
According to some experts, the shape of bite marks can give useful clues about
the person who caused the marks, as all mouths are different. However, forensic
odontologists need to be highly trained to be able to recognise and record bite marks,
and bite-mark analysis remains controversial. Some experts believe that comparisons
between dental records and bite marks are not valid because the conclusions
reached by different odontologists can vary, and often depend on personal experience
and judgment.
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Club leader notes crime lab
Activity 3:
Casting
Forensic dentists are specialists who analyse bite marks
left at crime scenes (more information about this is on
pages 47–48). They look at the shape of teeth and their
arrangement in the mouth, which can vary from individual to
individual. Identification is even easier when individuals have
numerous and complex dental treatments, as this gives their
dentition an additional uniqueness. Forensic scientists working on this type
of identification use the number, shape, type and placement of dental treatments
such as fillings and crowns, as well as unique differences in the structure of the teeth
and jaw, to reveal the person’s identity. Most of the time they analyse bite marks in
human skin, however it is not uncommon for partially eaten foodstuffs to be found
at the scene of crime as well. The foods most often found are fruit (such as apples),
cheese and chocolate.
Analysing saliva and DNA takes
longer and is more expensive
than bite mark identification.
Also, DNA can be contaminated.
So, if you go on a train and hold
somewhere you will have other
people’s DNA on your hand as
well, from people who’d touched
the same thing before.
Phil Marsden, forensic
odontologist, 2009
However, it is not only the bite mark itself that provides evidence for tracing the
suspect but also saliva. People deposit saliva on any surface during the process of
biting. Saliva contains white blood cells and sometimes even sloughed epithelial cells
that contain DNA. Police officers are able to locate stains from bodily fluids such as
saliva at the crime scene with high-intensity light sources and lasers. In addition,
modern techniques mean that even a small quantity of DNA can be enough to identify
the suspect when it is compared to his or her DNA profile. According to Phil Marsden,
a forensic dentist, DNA is not always the most useful tool.
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Club leader notes crime lab
Activity 3:
Casting
Forensic dentists use a special technique to analyse bite marks. First they take a
photo of the bite mark alongside a rigid scale, and then take an impression of the
suspect’s teeth with alginate powder. At this stage the dentists can’t compare bite
mark and impression as they are not matching like with like – the impression is a
‘negative’ of the bite mark. To get a ‘positive’ they have to cast the impression with
dental stone. Then they place the cast alongside a ruler on a flat scanner to get a 2D
image of it. The final step is printing the image on acetate sheet and putting it on top
of the photograph of the bite mark. This allows the dentists to compare the suspect’s
morphology with the bite mark left at the crime scene.
Links to everyday life
a. Dental records
Activity 3:
Casting
Most people are aware that dentists will add to their dental records at some stage in
their life. In the NHS (National Health Service), dentists have to keep your records for
at least two years, but they are advised to keep adult dental records for a minimum
of 11 years. Most dentists tend not to pass these records on to another dentist. This
is why another record of your teeth will be taken whenever you sign up with a new
dentist. If you send a written request to your dentist, you are entitled to receive a
copy and explanation of your records and X-rays within 40 days, provided that you pay
for them.
b. The work of a forensic dentist
Forensic odontology is the branch of forensic medicine dealing with the examination,
handling and presentation of dental evidence in a court of law. Dental bite-mark
analysis offers a rapid but cost-effective approach and can sometimes provide the
crucial piece of information to reveal the suspect’s identity. There are only about 30
actively practising and experienced forensic dentists in the UK. Phil Marsden is one
of them. He works as a dental surgeon three days per week and whenever needed as
a forensic dentist:
‘If you’re busy you do maybe 2–3 cases per month. But I still like doing the job as a
forensic dentist as you never know what the next phone call will bring.’
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Club leader notes crime lab
There are two main reasons why bite-mark analysis may not be taken into account.
First, police officers have to identify the bite marks at the crime scene, but not all of
them are trained for this, which means that they may miss such evidence. Second, the
amount of other evidence can be overwhelming.
Nevertheless, bite-mark analysis can be a crucial part of crime-scene investigation.
Phil says that one of the important roles of forensic dentists is to exclude innocent
people:
‘This can save a lot of time and money. And for people who are innocent it is important
as well, as they can sometimes only say “I didn’t do it” but are not able to provide any
evidence for their innocence.’
The job of the forensic dentist is similar to that of the dental surgeon in some areas.
Both take bite impressions, but a forensic dentist also has to be able to analyse the
impressions and present them to a court. This requires experience as well as
special training.
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Club leader notes crime lab
Activity 3:
Casting
Forensic dentists are also able to use dental records to identify dead bodies because
teeth survive most postmortem events, whereas other body tissues often do not. This
may help to identify a suspect or victim, but more often this type of body identification
has nothing to do with crime.
Links to the Science Museum
•T
he Science and Art of Medicine gallery: Can you find George Washington’s false
teeth? In this gallery you can learn more about the earliest false teeth.
•W
ho am I? gallery: Find out more about what makes you unique, but also what you
have in common with other humans and species.
Links to the National Curriculum and Scottish Curriculum
The activities in the box are designed to enrich and extend your classroom activities,
but they also have some strong links to the UK and Scottish curricula if you wish to
use them. We have listed the ones that we feel are most relevant, but you may find
others, particularly if they relate to other classroom activities that your students are
familiar with. Forensic science also appears as a theme in general programmes of
study, and this activity can extend this theme.
Activity 3:
Casting
UK National Curriculum KS3
Science
1.1. Scientific thinking
b. Critically analysing and evaluating evidence from observations and experiments.
2.1. Practical and enquiry skills
Pupils should be able to:
b. assess risk and work safely in the laboratory, field and workplace.
c. plan and carry out practical and investigative activities, both individually and in
groups.
2.2. Critical understanding of evidence
Pupils should be able to:
b. evaluate scientific evidence and working methods.
4. Curriculum opportunities
Pupils should be able to:
a. research, experiment, discuss and develop arguments.
b. pursue an independent enquiry into an aspect of science of personal interest.
c. use real-life examples as a basis for finding out about science.
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Club leader notes crime lab
Scottish Curriculum for Excellence
Topical science
SCN 4-20a
I have researched new developments in science and can explain how their current or
future applications might impact on modern life.
Activity 3:
Casting
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Club leader notes crime lab
Extension ideas
a. Another forensic casting activity: shoe prints
This activity allows your students to strengthen their observation skills by offering
them another object such as a shoe to cast and identifying its features.
For this activity, you will need at least one shoe and one shoebox per group (if students
want to have their own casts they can even bring in one of their old shoes and a box).
Every student group will also need black tempera paint, a paint brush, a white sheet of
paper, sand or compost, water and casting material such as plaster of Paris.
Students’ should:
1. Paint the bottom of their shoe with black tempera paint.
2. Make a print of the sole of their shoe by placing it on a large sheet of white paper,
and write their name on the back of the sheet.
4. Add water to plaster of Paris (or another casting material such as alginate powder)
and mix the ingredients together.
5. Continue stirring until the mixture is the consistency of thick cream, and then
carefully pour it into the impression. (Hint: plaster of Paris will need to dry overnight.)
6. Remove the shoebox when the cast is dry, then clean it and write their name on the
back of the shoe print.
You can mix up all your students’ casts and then ask them whether they are able to
match them to the correct shoe print. Or, make one extra set of shoe prints for the
next session and see whether your students are able to identify the shoe you used for
the print.
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Club leader notes crime lab
Activity 3:
Casting
3. Fill half the box with damp sand or compost – this is the surface onto which they
press the shoe.
b. Make your DNA visible
For this activity, your students need water, 6% salt solution, alcohol and some of their
own cheek cells, which contain DNA and are easy to get.
Students should:
1. Swill 5 ml of water in their mouth for about 30 seconds to make some of their cheek
cells come away and float in the water. Ask them to spit the water containing cheek
cells into a cup, and then transfer it to a test tube.
2. Add 1 ml of 6% salt solution to the tube, which will help prevent the DNA molecules
from repelling each other later. The positive sodium (Na+) ions from the salt
neutralise the negative charges of the phosphates in DNA.
3. Add 1 ml of 25% soap solution (e.g. washing-up liquid) and gently mix all the tube
contents. The soap is important as it can break the cell membranes. As a result, the
contents of the cells and the cell nuclei are released.
This method of DNA extraction also works well with onion or kiwi fruit.
c. What else can you make a cast of?
Ask you students to bring other foods, such as banana, bread, etc., to see which foods
they can make the best casts with.
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Club leader notes crime lab
Activity 3:
Casting
4. Carefully add alcohol to the top of the tube without mixing the layers and watch the
DNA appear (it looks like cotton wool). This happens because DNA mixes with the
water but not with the alcohol. As a result, DNA molecules that happen to be near
the water/alcohol interface clump together and become visible.
What’s on the website?
sciencemuseum.org.uk/crimelabdownloads
Posters
There are posters for each of the three Crime Lab activities – the ‘Fuming fingerprints
activity’, ‘Swipe card activity’ and ‘Casting activity’ – on the website. We have learned
from teachers involved in this project that using posters to advertise club sessions
in your school can help to get more students interested in attending your club. The
posters have been designed to look good whether they are printed in colour or in black
and white.
On the website you will find two different poster files per activity. The first file
is a PDF document. When printing it out you will find a blank box on the poster on
which you can write the date, time and location of your club session. The second file
includes a Word box, which allows you to type the date, time and location on the
poster electronically. Only use this version if you want to type your information
before printing.
Film
We recommend that you show the film at the beginning of the club session when you
first start one of the activities from the Crime Lab box. You may also want to show it
whenever you start a new activity, to provide newcomers with this information as well.
PowerPoint presentations
From focus-group sessions with teachers we learned that club leaders like you often
use PowerPoint presentations to introduce an activity in their clubs and to capture
their students’ interest right from the beginning of the session. Therefore, we have
provided some slides about links to real life to make the content of the activities more
relevant and exciting for your students. Instructions on additional slides will help you
and your students run the activities smoothly. The PowerPoint files still allow you
to hide or add slides if you wish, so you can use them in whatever way best suits the
needs of your group.
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Club leader notes crime lab
What’s on the
website?
The three-minute video clip has been developed to set the scene and provide an
overarching theme that combines the ‘Fuming fingerprints’, ‘Swipe card’ and ‘Casting’
activities. Moreover, we have found that it can increase your students’ motivation to
return for future club sessions.
Student logbook
The purpose of the student logbooks is not only to allow your students to record their
findings but also to give them something to take home from their club sessions. The
student logbooks have been designed to look good whether they are printed in colour
or in black and white.
Follow the instructions below on how to assemble the logbooks.
1. Print the student logbooks out doublesided (this is very important).
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Club leader notes crime lab
What’s on the
website?
2. Stack the three sheets on top of each
other so that page numbers 1, 3 and
5 are in the left-hand corner at the
bottom. Make sure that the sheet with
page number 1 is at the bottom, 3 is in
the middle and 5 is on the top.
3. Keep the sheets in the same order
when folding them from A4 to A5
format.
4. When stapling everything together, try
to get as close to the edge as you can.
Reorder sheet
The materials in this box are a combination of readily available components and less
common items that have been developed specifically for the activities. They’re designed
to be predominantly reusable, but you can reorder individual items as required.
This sheet gives you the costs and codes of the unique or consumable materials
included in this box to enable you to order more as desired at:
reorder@sciencemuseum.org.uk
You can order further Mars Mission or Crime Lab boxes at:
sciencemuseum.org.uk/scienceboxes
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Club leader notes crime lab
What’s on the
website?
Having trouble printing your logbooks? For troubleshooting tips go to
‘Printing the resources’ at: sciencemuseum.org.uk/scienceboxes
Links to websites for further research
If you wish to find out more about certain topics we recommend the
following websites (information correct as of July 2009):
Reference for crime-scene investigation
crimeandclues.com/index.htm
(Also see the book Forensics for Dummies by Douglas P Lyle, ISBN 978 0764555800)
References for fuming fingerprints
answers.uk.com/services/fingers2impressions.html
handresearch.com/news/how-fingerprinting-works.htm
http://scienceandresearch.homeoffice.gov.uk/hosdb/fingerprints-footwear-marks/
fingerprinting-methods
Superglue for cuts
http://sportsmedicine.about.com/od/treatinginjuries/a/supergluecuts.htm
Why superglue doesn’t stick to the tube
answerbag.com/q_view/67563
Fingerprints on ID cards
direct.gov.uk/en/Nl1/Newsroom/DG_171978
mutr.co.uk/product_info.php?products_id=1009343
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Club leader notes crime lab
Links to websites for
further research
Peltier cells
Fingerprints and fingerprint scanners
http://computer.howstuffworks.com/fingerprint-scanner.htm/printable
References for swipe cards
tryengineering.org/lessons/crackingthecode.pdf
barcoding.com/information/barcode_history.shtml
uspto.gov/nmti/recipients_92.html
http://news.bbc.co.uk/1/hi/technology/6570871.stm
gomonews.com/mobile-barcodes-101-understanding-mobile-barcodes
References for casting
healthyteeth.org/experiments/hiddenSugar.html (extension ideas)
dentalhealth.org.uk/faqs/leafletdetail.php?LeafletID=30 (dental records)
bafo.org.uk (British Association for Forensic Odontology)
Links to websites for
further research
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Club leader notes crime lab
Information for the crime story
We have provided you with two different versions of our crime story that we
specifically designed for this box.
Version 1
Version 1 requires your students to investigate all three pieces of evidence before they
can work out ‘whodunnit’.
Ask your students to write their findings in their logbook. This way of recording will
make it easier to identify the thief.
How to prepare for all three activities
1. Fuming fingerprints
a. Get four volunteers, suspects A, B, C and D, who are not members of your club
(you could be one of them yourself), to leave a fingerprint on the information sheet
about the suspects (see page 62). The thief is suspect C. In the crime story the
suspects are all male, but your volunteers do not have to be. The easiest ways to
record fingerprints are to rub the thumb over a thick layer of graphite from a pencil
applied on a piece of paper, or to use an ink stamp pad. Make sure that all the
volunteers use the same thumb, e.g. their left thumb. Now press the dirty thumb on
a small piece of sticky tape, which you then lift and place in the intended box on the
information sheet. Repeat this process until you have completed a sheet of the four
fingerprints for each of the five student groups.
b. Using gloves to avoid leaving more fingerprints, cut the plastic sheet into small
rectangles, about the size of a microscope slide. Then, all of your volunteers
should touch one plastic slide with their left thumb. Make sure that no-one else
(including lab technicians and your club members) touches these slides unless
wearing gloves.
Information for
the crime story
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Club leader notes crime lab
2. Swipe card
These are the codes you should use to programme the magnetic-strip cards:
Code for suspect A: 11.00pm
pm 11 hours 0 minutes end
Code for suspect B: 9.15am (this suspect is lying about the time in his statement)
am 9 hours 15 minutes end
Code for suspect C, the thief: 4.45am (this suspect is lying about the time in his statement)
am 4 hours 45 minutes end
15 minutes end
Code for suspect D: 11.15am
am 11 hours Information for
the crime story
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Club leader notes crime lab
3. Casting
Get four volunteers, suspects A, B, C and D, who are not members of your club
(you could be one of them yourself), to leave a bite mark on one piece of Plastazote
(following the same instructions as for students – see page 39). In the crime story the
suspects are all male, but your volunteers do not have to be. Make sure you label the
Plastazote sheets A, B, C and D. Then ask the volunteer who is suspect C (the thief) to
take a really big bite from an additional apple – this will be your piece of evidence from
the ‘crime scene’. You can help preserve it by sprinkling it with lemon juice.
Information about the suspects (information for students)
Print pages 61 to 68 and hand them out to your students. They will need this
information to solve the crime.
Information for
the crime story
60
Club leader notes crime lab
Solve the crime!
Background
In the early hours of this morning, at 4.45am according to CCTV footage, an attempted
robbery took place in the Science and Art of Medicine gallery on the fifth floor of the
Science Museum. Following the report of the robbery attempt, the police identified
four male suspects who may have had the opportunity to commit the crime.
All of them had access to the gallery at around the time CCTV caught the thief. As
all four suspects are Museum staff and none of them look like the man shown in
the footage (apart from posture and height), the police are convinced that the thief
disguised himself during the attempted robbery. This would have protected him
from being recognised by other members of staff when the CCTV footage was viewed
afterwards. But police officers still have three different pieces of evidence that may
lead them to the identity of the thief.
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Club leader notes crime lab
Information for
the crime story
Now it’s the job of the specialists to investigate the evidence further.
Fingerprints
CCTV footage shows that the suspect touched the case when he heard the alarm. It
seems that he wasn’t wearing his gloves at this time. Have his fingerprints been left
on the case?
Police officers have removed a thin plastic protective layer from the case. Now it’s
time for fingerprint specialists to find out whether there are fingerprints on the plastic
layer and who they belong to. Whose fingerprint was on this case?
Suspect Fingerprint (left thumb)
Yes
No
Suspect A
Suspect B
Suspect C
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Club leader notes crime lab
Information for
the crime story
Suspect D
Swipe card
Police officers can’t check whether the suspects were in the gallery during the day. But
they can still investigate whether they were in the gallery at night. The thief had to use a
swipe card to get into the gallery at night and the time when he used it to leave the gallery
will still be stored on his card. That’s why the thief should have a time on his card that is
around 4.45am.
All four suspects work at the Science Museum and therefore they are all in possession of
swipe cards, which have been sent to the Crime Lab for analysis. Their homes and work
areas have been searched, but no tools or suspicious clothing were found. While Scene
of Crime Officers searched the crime scene for evidence, detectives questioned the
four suspects.
The information held on the swipe cards will help the detectives to determine whether the
suspects tell the truth during the interviews. Record your results in your student logbook
or in the table provided to help identify who the thief is.
Here are the suspects’ statements...
SUSPECT A
Warder
Time code on swipe card:
‘I was working a night shift last night and it’s my job to
check that all the galleries are secure, so of course I
was there. I left the medicine gallery at around 11pm.
I was on duty all night but I had other galleries to
check so I didn’t go back there because everything
looked fine when I last checked it. I left the Museum
at 7.30am this morning.’
The story checks out, but could the suspect have slipped away, got
changed, attempted the robbery, and then changed back and completed
his night duty? If so, the time on his card won’t back up his statement that
he left the gallery at 11pm.
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Club leader notes crime lab
Information for
the crime story
Is the suspect telling the truth?
SUSPECT B
Museum Curator
Time code on swipe card:
‘I went out for a meal last night, then went home
alone. As I had a dentist appointment in the
afternoon I came into work this morning at 7.15am,
which is earlier than usual. I went immediately
to the fifth floor because I wanted to get some
information about mummies before it got too busy
in the Science and Art of Medicine gallery. A friend
of mine who works as an archaeologist had asked
me for that information and she needed it urgently. I
had to leave the Museum at 2pm as I had to be at the
dentist’s in Covent Garden at 2.45pm.’
Is the suspect telling the truth?
Suspect B doesn’t have any alibi for the night, but his friend agrees that
she asked him for some information about mummies. He might be telling
the truth, but it could be that he only pretended to come to work early
because he had to find somewhere to hide the equipment shown on CCTV.
Information for
the crime story
64
Club leader notes crime lab
SUSPECT C
Gallery Maintenance Technician
Time code on swipe card:
‘My wife is on holiday and that’s why I was planning
to go out with some of my friends yesterday evening.
But in the end I decided to stay at home, have pasta
for dinner and watch a DVD because I had to come
to the Science Museum early today, at 7am. I was
working an early shift and had to repair some
exhibits on the fifth floor, right next to the gallery. It
took me about an hour or so to fix them. After that,
at about 8am, I went back to the office, where I had
breakfast with my colleagues as usual.’
Is the suspect telling the truth?
The suspect’s colleagues agreed that they all had breakfast together
at about 8am. However, suspect C has no witnesses for last night. If he
was the thief and he is lying about fixing the exhibits at about 7am in the
morning an earlier time will have been captured on his swipe card.
Information for
the crime story
65
Club leader notes crime lab
SUSPECT D
Learning Resources Coordinator
Time code on swipe card:
‘I did go to the Science and Art of Medicine gallery
yesterday morning because I gave a talk about the
materials used in prosthetic eyeballs to members of
staff from 10.15 to 11.15am. After that I didn’t enter
the gallery again. However, I feel that it’s important
for you to know that I didn’t leave the Museum until
12pm today as I was helping out on Science Night last
night. About 400 kids who stayed over as well as loads
of staff can verify my story. We were sleeping in the
Exploring Space gallery on the ground floor, which
is probably why we didn’t hear anything. I didn’t even
know there was a robbery attempt until I saw it on the
news back at home today.’
Is the suspect telling the truth?
Can you help the detectives to find out who is telling the truth and who is lying?
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Club leader notes crime lab
Information for
the crime story
There was a Science Night sleepover in the Museum and the suspect was
working, but none of the witnesses can vouch for him at all times during the
night. Maybe he slipped away and returned to the sleeping area later? Could
he have hidden the tools and clothes in his sleeping bag? His card shows the
time he last left the gallery, but not the day – so it could have been yesterday
as he states, or it could have been today.
Suspect
Time on Statement
Statement
swipe card
true
false
Suspect A
Suspect B
Suspect C
Suspect D
Information for
the crime story
67
Club leader notes crime lab
Apple with bite mark
Police officers also found an apple with a big bite mark left behind at the crime scene.
The CCTV footage shows that the thief bit into an apple while walking through the
gallery, and a similar apple seemed to fall out of his bag when he was trying to escape
quickly. Can you find out if this apple belonged to one of our four suspects?
Suspect
Yes
No
Suspect A
Suspect B
Suspect C
Suspect D
Information for
the crime story
68
Club leader notes crime lab
Version 2
Version 2 allows you to deliver the activities in stand-alone form. Students will be
able to identify the thief after they have done one of the activities. This version is only
recommended when you are not planning to run the activities consecutively with the
same students.
Ask your students to record their results in their student logbooks or in the table
provided to help identify who the thief is.
Version 2: Fuming fingerprints
How to get prepared (club leader information)
a. Get four volunteers, suspects A, B, C and D, who are not members of your club (you
could be one of them yourself), to leave a fingerprint on the information sheet about
the suspects (see page 71). In the crime story the suspects are all male, but your
volunteers do not have to be. The easiest ways to record fingerprints are to rub the
thumb over a thick layer of graphite from a pencil applied on a piece of paper, or to
use an ink stamp pad. Make sure that all the volunteers use the same thumb, e.g.
their left thumb. Now press the dirty thumb on a small piece of sticky tape, which
you then lift and place in the intended box on the information sheet. Repeat this
process until you have completed a sheet of the four fingerprints for each of the
five groups.
b. Using gloves to avoid leaving more fingerprints, cut the plastic sheet into small
rectangles, about the size of a microscope slide. Then, only one of the volunteers
(the ‘criminal’) touches one plastic slide per group with his or her left thumb. Make
sure that no-one else (including lab technicians and your club members) touches
these slides unless wearing gloves.
Information about the suspects (information for students)
Print pages 70 and 71 and hand them out to your students. They will need this
information to solve the crime.
Information for
the crime story
69
Club leader notes crime lab
Solve the crime! (Fuming fingerprints activity)
Background
In the early hours of this morning, at 4.45am according to CCTV footage, an attempted
robbery took place in the Science and Art of Medicine gallery on the fifth floor of the
Science Museum. Following the report of the robbery attempt, the police identified
four male suspects who may have had the opportunity to commit the crime.
All of them had access to the gallery at around the time CCTV caught the thief. As
all four suspects are Museum staff and none of them look like the man shown in
the footage (apart from posture and height), the police are convinced that the thief
disguised himself during the attempted robbery. This would have protected him
from being recognised by other members of staff when the CCTV footage was viewed
afterwards. But police officers still have one piece of evidence that may lead them to
the identity of the thief.
Now it’s time for fingerprint specialists to find out whether there are fingerprints on
the plastic layer and who they belong to. Whose fingerprint was on this case?
70
Club leader notes crime lab
Information for
the crime story
CCTV footage also shows that the suspect touched the case when he heard the alarm.
It seems that he wasn’t wearing his gloves at this time. Have his fingerprints been left
on the case? Police officers have removed a thin plastic protective layer from the case.
Suspect Fingerprint (left thumb)
Yes
No
Suspect A
Suspect B
Suspect C
Suspect D
In reality more evidence is needed to lead to a conviction, so other kinds of evidence
left at the crime scene, witness statements and other forms of proof are required to
construct a solid case against any suspect.
71
Club leader notes crime lab
Information for
the crime story
Quick note
Version 2: Swipe card
How to prepare (club leader information)
These are the codes you should use to programme the magnetic-strip cards:
Code for suspect A: 11.00pm
pm 11 hours 0 minutes end
Code for suspect B: 9.15am (this suspect is lying about the time in his statement)
am 9 hours 15 minutes end
Code for suspect C, the thief: 4.45am (this suspect is lying about the time in his statement)
am 4 hours 45 minutes end
15 minutes end
Code for suspect D: 11.15am
am 11 hours Information about the suspects (information for students)
Print pages 73 to 78 and hand them out to your students. They will need this
information to solve the crime.
Information for
the crime story
72
Club leader notes crime lab
Solve the crime! (Swipe card activity)
Background
In the early hours of this morning, at 4.45am according to CCTV footage, an attempted
robbery took place in the Science and Art of Medicine gallery on the fifth floor of the
Science Museum. Following the report of the robbery attempt, the police identified
four male suspects who may have had the opportunity to commit the crime.
All of them had access to the gallery at around the time CCTV caught the thief. As
all four suspects are Museum staff and none of them look like the man shown in
the footage (apart from posture and height), the police are convinced that the thief
disguised himself during the attempted robbery. This would have protected him
from being recognised by other members of staff when the CCTV footage was
viewed afterwards.
Police officers can’t check whether the suspects were in the gallery during the day.
But they can still investigate whether they were in the gallery at night. The thief had
to use a swipe card to get into the gallery at night and the time when he used it to
leave the gallery will still be stored on his card.
73
Club leader notes crime lab
Information for
the crime story
All four suspects work at the Science Museum and therefore they are all in possession
of swipe cards, which have been sent to the Crime Lab for analysis. Their homes and
work areas have been searched, but no tools or suspicious clothing were found. While
Scene of Crime Officers searched the crime scene for evidence, detectives questioned
the four suspects.
The information held on the swipe cards will help the detectives to determine whether
the suspects tell the truth during the interviews. Record your results next to each
suspect’s statement to help you decide who the culprit is.
Here are the suspects’ statements...
SUSPECT A
Warder
Time code on swipe card:
‘I was working a night shift last night and it’s my job to
check that all the galleries are secure, so of course I
was there. I left the medicine gallery at around 11pm.
I was on duty all night but I had other galleries to
check so I didn’t go back there because everything
looked fine when I last checked it. I left the Museum
at 7.30am this morning.’
Is the suspect telling the truth?
The story checks out, but could the suspect have slipped away, got
changed, attempted the robbery, and then changed back and completed
his night duty? If so, the time on his card won’t back up his statement that
he left the gallery at 11pm.
Information for
the crime story
74
Club leader notes crime lab
SUSPECT B
Museum Curator
Time code on swipe card:
‘I went out for a meal last night, then went home
alone. As I had a dentist appointment in the
afternoon I came into work this morning at 7.15am,
which is earlier than usual. I went immediately
to the fifth floor because I wanted to get some
information about mummies before it got too busy
in the Science and Art of Medicine gallery. A friend
of mine who works as an archaeologist had asked
me for that information and she needed it urgently. I
had to leave the Museum at 2pm as I had to be at the
dentist’s in Covent Garden at 2.45pm.’
Is the suspect telling the truth?
Suspect B doesn’t have any alibi for the night, but his friend agrees that
she asked him for some information about mummies. He might be telling
the truth, but it could be that he only pretended to come to work early
because he had to find somewhere to hide the equipment shown on CCTV.
Information for
the crime story
75
Club leader notes crime lab
SUSPECT C
Gallery Maintenance Technician
Time code on swipe card:
‘My wife is on holiday and that’s why I was planning
to go out with some of my friends yesterday evening.
But in the end I decided to stay at home, have pasta
for dinner and watch a DVD because I had to come
to the Science Museum early today, at 7am. I was
working an early shift and had to repair some
exhibits on the fifth floor, right next to the gallery. It
took me about an hour or so to fix them. After that,
at about 8am, I went back to the office, where I had
breakfast with my colleagues as usual.’
Is the suspect telling the truth?
The suspect’s colleagues agreed that they all had breakfast together
at about 8am. However, suspect C has no witnesses for last night. If he
was the thief and he is lying about fixing the exhibits at about 7am in the
morning an earlier time will have been captured on his swipe card.
Information for
the crime story
76
Club leader notes crime lab
SUSPECT D
Learning Resources Coordinator
Time code on swipe card:
‘I did go to the Science and Art of Medicine gallery
yesterday morning because I gave a talk about the
materials used in prosthetic eyeballs to members of
staff from 10.15 to 11.15am. After that I didn’t enter
the gallery again. However, I feel that it’s important
for you to know that I didn’t leave the Museum until
12pm today as I was helping out on Science Night last
night. About 400 kids who stayed over as well as loads
of staff can verify my story. We were sleeping in the
Exploring Space gallery on the ground floor, which
is probably why we didn’t hear anything. I didn’t even
know there was a robbery attempt until I saw it on the
news back at home today.’
Is the suspect telling the truth?
Can you help the detectives to find out who is telling the truth and who is lying?
77
Club leader notes crime lab
Information for
the crime story
There was a Science Night sleepover in the Museum and the suspect was
working, but none of the witnesses can vouch for him at all times during the
night. Maybe he slipped away and returned to the sleeping area later? Could
he have hidden the tools and clothes in his sleeping bag? His card shows the
time he last left the gallery, but not the day – so it could have been yesterday
as he states, or it could have been today.
Suspect
Time on Statement
Statement
swipe card
true
false
Suspect A
Suspect B
Suspect C
Suspect D
Quick note
In reality more evidence is needed to lead to a conviction, so other kinds of evidence
left at the crime scene, witness statements and other forms of proof are required to
construct a solid case against any suspect.
Information for
the crime story
78
Club leader notes crime lab
Version 2: Casting
How to prepare (club leader information)
Get four volunteers, suspects A, B, C and D, who are not members of your club
(you could be one of them yourself), to leave a bite mark on one piece of Plastazote
(following the same instructions as for students – see page 39). In the crime story all
the suspects are male, but your volunteers do not have to be. Make sure you label the
Plastazote sheets A, B, C and D. Then ask the volunteer who is suspect C (the thief) to
take a really big bite from an additional apple – this will be your piece of evidence from
the ‘crime scene’. You can help preserve it by sprinkling it with lemon juice.
Information about the suspects (information for students)
Print pages 80 and 81 and hand them out to your students. They will need this
information to solve the crime.
Information for
the crime story
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Solve the crime! (Casting activity)
Background
In the early hours of this morning, at 4.45am according to CCTV footage, an attempted
robbery took place in the Science and Art of Medicine gallery on the fifth floor of the
Science Museum. Following the report of the robbery attempt, the police identified
four male suspects who may have had the opportunity to commit the crime.
All of them had access to the gallery at around the time CCTV caught the thief. As
all four suspects are Museum staff and none of them look like the man shown in
the footage (apart from posture and height), the police are convinced that the thief
disguised himself during the attempted robbery. This would have protected him
from being recognised by other members of staff when the CCTV footage was
viewed afterwards.
Police officers also found an apple with a big bite mark left behind at the crime scene.
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Club leader notes crime lab
Information for
the crime story
The CCTV footage shows that the thief bit into an apple while walking through the
gallery, and a similar apple seemed to fall out of his bag when he was trying to escape
quickly. Can you find out if this apple belonged to one of our four suspects?
Suspect
Yes
No
Suspect A
Suspect B
Suspect C
Suspect D
Quick note
In reality more evidence is needed to lead to a conviction, so other kinds of evidence
left at the crime scene, witness statements and other forms of proof are required to
construct a solid case against any suspect.
Information for
the crime story
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Club leader notes crime lab
Thank you!
We would like to thank the following people and organisations who willingly gave up
their time and shared their expertise to make this project a success.
BP for its generous support of this project
Science and Engineering Club boxes
teacher panel and their students:
STEMNET
Steve Smythe, Diversity and Development
Phil Griffith
Bramhall High School, Stockport
Home Office Scientific Development
Branch
Emma Upton-Swift and Emily Kempthorne
Bridge Academy, London
Steve Bleay, Higher Scientific Officer
BAFO – The British Association for
Forensic Odontology
Christina O’Brien
Dunraven School, London
Philip Marsden, dental surgeon and
practising forensic odontologist
Tom Ward
Elstree School, Reading
kaiclear.com
Emma Doyle and Elaine Armstrong
Maidstone Grammar School for Girls, Kent
Kai Clear, film director and editor
Illumina Digital
Jasbir Singh Lota
Parmiter’s School, Hertfordshire
Sabrina Organo, film editor and
graphic artist
Helen Murtagh
St Angela’s Ursuline School, London
We would particularly like to thank the
Middlesex University Teaching Resources
team, led by Professor John Cave,
Kate Johns and Peter Stensel, for their
assistance with the development of the
materials used in the activities.
Barry Scott
Southgate School, Hertfordshire
Lubna Pervaze
Tom Hood Community Science College,
London
British Science Association
Adrian Fenton, Young People’s
Programme Manager
Matthew Tosh, Science and Engineering
Clubs Coordinator
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Club leader notes crime lab