Pre-Trial Procedures
The Criminal Investigation
Expectations
By the end of this lesson students will be able to:
• 1. Explain pre-trial procedures, including processing evidence (fingerprints)
• 2. Explain the processes of police investigation (as it relates to fingerprint
evidence)
• 3. Create and classify your own fingerprints
Catholic Graduate Expectations
1. A repsonsible citizen who respects the environment and uses resources
wisely
2. A reflective, creative and holistic thinker who thinks reflectively and
creatively to evaluate situations and solve problems
The Crime Scene
• Police have the right to section off the crime
scene to make sure no evidence is lost or
tampered with.
• Police can refuse entry to a crime scene.
• HOWEVER, if the incident involves a death,
the coroner has jurisdiction over the area.
The Crime Scene Continued
• The area will be photographed and searched for
items such as hair or fiber samples, blood, forced
entry, physical struggle, fingerprints, footprints,
or weapons
• This is called forensic evidence.
• Police will also question witnesses about their
knowledge of the crime or the persons involved.
When did the use of Fingerprints
start in Law?
• There is evidence of fingerprints in ancient
times i.e. in 2000 BCE in the building of
pyramids
• In the 3rd century BCE the Chinese used
fingerprints to authorize legal documents
which could be used in litigation
William James Herschel
• William James Herschel was an English Administrator
who was the first to implement the practical
application of fingerprinting
• In 1858 he used fingerprints (or an entire handprint
in this case) to solidify a legal contract in order to
prevent the other party from denying his signature at
a later date.
Dr. Henry Faulds
• However a Scottish doctor in 1874 by the name of Henry
Faulds is arguably the more common person known as the
“Father of Fingerprinting”.
• He kept extensive records of various fingerprints and
concluded that fingerprints were unchangeable and
immutable .
• Was also the first person who was able to lift a print off a
whiskey bottle and identify it.
(Source: http://www.fingerprinting.com/history-of-fingerprinting.php)
Processing Physical Evidence:
Fingerprints
• Forensic scientists analyze the information
collected.
• Fingerprints are compared with those on file
at the RCMP central repository in Ottawa.
– The patterns of ridges on our finger pads are
unique: no two individuals—even identical
twins—have fingerprints that are exactly alike.
(Like a snowflake!)
Fingerprints continued…
• Injuries such as burns or scrapes will not
change the ridge structure: when new skin
grows in, the same pattern will come back.
• Dactyloscopy the practice of using
fingerprints to identify someone.
Dusting for Fingerprints
• It is extremely important that specialists are able
to properly dust and lift fingerprints at a crime
scene to be able to classify and match them to
those in the database.
• Dusting is a method that is used to lift prints from
hard surfaces
• Chemicals are needed to lift prints off smooth
surfaces
Problems with Fingerprint Evidence
• Mistakes can be made in fingerprint identification
usually only a portion of a print is available and can
be distorted and hard to read, especially in a messy
crime scene situation (i.e., BLOOD!)
• It is extremely important that specialists are able to
properly dust and lift fingerprints at a crime scene to
be able to classify and match them to those in the
database.
How are Fingerprints Classified?
Are we able to classify our own
fingerprints in class?
YES!
Classifying Fingerprints
• All fingerprints can be identified as one of
three types: Arches, Loops, Whorls
– Arches: forming ridges that run from one side of
the print to the other and curve up the middle
Loops
• Loops: showing stronger curves than arches
with ends that start on one side of the finger,
loop around and end up in the same place
• Don’t get these confused with full circles or
ovals.
Whorls
• Whorls: forming complete ovals, often in a
spiral pattern around a central point.
Your turn! Directions:
• Print your name on the fingerprint card.
• I will bring each group an ink pad, classification
handout and comparison organizer.
• Roll each finger on the ink pad so the entire fingerprint
pattern area is evenly covered with ink.
• Generally, the weight of the finger is the maximum
pressure needed to clearly record a fingerprint.
• Roll each finger from nail to nail in the appropriate
space, taking care to lift each finger up after rolling to
avoid smudging.
• Label the fingerprint to identify which finger you have
printed (i.e., Index or I) and classify your print
Classification: Compare Yours
Most Common Fingerprints
• Ulnar loop = a loop that comes from the pinky
side of the hand
– So common, it is quite rare NOT to have one!
• Whorl = a spiral pattern
– Very common, especially on the thumb, index
and ring fingers
• Radial loop = a loop that comes from the thumb
side of the hand
– Commonly found on index finger, uncommon on
middle finger, rare on other fingers
Uncommon Fingerprints
• Arch = most simple fingerprint, no loop patterns
– Uncommon pattern on: all fingers, rare on little
finger
• Double loop = two loops going in two directions,
but is actually a type of whorl
– Uncommon pattern on: all fingers except
thumb, rare on ring and little fingers
• Peacock’s eye = a tiny whorl inside a loop
– Uncommon pattern on: all fingers, most
common on ring finger, rare on thumb.
Rare Fingerprints
• Tented arch = arch pattern but horizontal ridges rising
up high in the middle, creating a tent-like pattern.
Note: the tented arch is often confused with a loop
that looks like a tented arch. Look for any signs of a
loop to check if it is a ‘real’ tented arch.
– Rare on all fingers, extremely rare on thumb and little
finger
• Accidental = anything else, such as horizontal rather
than vertical loops
– Rare on index finger, extremely rare on all other
fingers
What do your Fingerprints
say about You?
Hand readers have associated fingerprints with certain character traits.
•
•
•
•
•
•
•
Loops*: flexible, adaptable, easy going, highly receptive, impressionable,
unfocussed, team players.
Arches: down to earth, pragmatic, responsible, reserved, consistent.
Tented arches: hyperactive, impulsive, intense, fiery.
Whorls*: independent, inflexible, individualistic, highly focussed.
Double loop (a.k.a. composite): indecisive, uncertain, diplomatic. Some double
loops look more like whorls, others are more clearly two intertwined loops.
Depending on which one it is, see also the associated loop or whorl characteristics.
Peacock’s eye (a.k.a. central pocket loop): perfectionistic, good eye for detail. It is
more of a whorl than a loop, so see also whorl characteristics.
*Note that loops and whorls are quite common – so it would take about 4+ whorls
to make you a ‘whorly’ person and 7+ loops to make you a ‘loopy’ person.
Character Traits Continued…
•
Hand readers also give specific meaning to the fingers. To interpret the meaning, you
need to combine all the characteristics, and this takes experience (say, getting people’s
feedback from reading at least 1000 hands). But it can be fun linking the fingerprints
characteristics to the individual fingers:
•
•
•
•
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Thumb: Willpower/control
Index: Public image, self-expression
Middle finger: Values, morals
Ring finger: Aesthetics, creativity
Pinky: Communication
•
The meaning also depends on the hand you look at – this is if you have different
fingerprints on your left hand compared to your right hand:
•
•
Dominant hand (right if right handed): Public self
Passive hand: Private self
•
Source: Meaning of fingerprints. | we must know. (n.d.). Retrieved from: https://wemustknow.wordpress.com/2010/03/27/meaning-offingerprints/