Crime Scene Investigation
Course
Forensic Science
Unit IV
Crime Scene
Investigation
Rationale
Crime Scene Investigation is critical to the criminal justice system. The role
of the crime scene investigator is critical in obtaining, photographing, and
preserving evidence at a crime scene. An understanding of crime scene
investigation is crucial for the forensic scientist to further analyze the crime
and suspect.
Essential
Question
What procedures
are implemented
at a crime scene
and why are they
important?
Objectives
The student will be able to:
1. Work as a productive member of a team.
2. Conduct a systematic search of a mock crime scene.
3. Develop a crime scene sketch.
4. Demonstrate proper techniques of collecting and packaging evidence
at a crime scene.
TEKS
§130.295(c)
(1)(A)(B)
(2)(F–H)
(3)(A–F)
(5)(A–J)
(6)(A)
Engage
Show a crime scene clip of your choice (if a video is not available, you can
role play a crime scene investigator that does not follow protocol). Have
students discuss the procedures that they feel are true to crime scene
investigation and those they feel are not true. Use the Discussion Rubric for
assessment.
Prior Student
Learning
– Safety and the
Scientific
Method
– Careers and
History of
Forensic
Science
Estimated Time
5 to 6 hours total
– 50 min. lecture
– 2–3, 50 min.
mock crime labs
– 50 min. room
sketch
– 50 min. final
sketch
– 50 min. review
Key Points
I. Process a Crime Scene
A. Isolate and secure the scene
B. Document the scene
C. Search for the evidence
D. Collect and package the evidence while maintaining the chain of
custody
E. Submit the evidence for analysis
II.
First Officer on the Scene
A. A – Assess the crime scene and assist the injured
B. D – Detain the witness(es)
C. A – Arrest the perpetrator
D. P – Protect the crime scene
E. T – Take notes
III. Secure the Crime Scene
A. Look for signs of life
B. Cordon off the scene (only allow authorized personnel in)
C. Bodies should be certified as “dead” by a medical examiner (ME)
before being moved
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IV. Survey the Crime Scene
A. A walkthrough is performed by the crime scene investigator, the
first officer, and sometimes the lead detective
B. Record initial observations of who, what, where, when, and how
C. Make a plan of action
V.
Document the Crime Scene
A. Record the crime scene and potential evidence with
1. Notes – record the following while at the crime scene (details
are the key)
(1) Date
(2) Time
(3) Description of the location, weather, and environmental
conditions
(4) Description of the crime
(5) Location of the evidence relative to other key points
(6) Names of all people involved
(7) Any other relevant information
2. Photography
(1) Nothing should be moved until photographed
(2) Take photos of the scene and the surroundings
(3) Photograph entrances and exits
(4) Use wide and close-up photos
(5) Use various angles of each piece of evidence
(6) Use a ruler to show size
3. Sketches – draw a rough sketch at the scene (reconstruct a
better one later) including
(1) Date, time, and location
(2) Scale
(3) Recovered items
(4) Important features
(5) Accurate distance measurements of objects (from two
fixed points)
(6) A legend for the description of items
(7) A compass designating north
(8) Names of the investigators, victims, and suspects
4. Videography
(1) Narrate the video
(2) Be objective
(3) Record from different perspectives
VI. Measuring Techniques
A. Triangulation
1. For each piece of evidence being recorded, use two
permanent objects as reference points that are not likely to be
moved
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2. The two reference points and the piece of evidence form a
triangle, hence the term triangulation
3. Whatever object you are measuring to or from, use the same
spot on the object every time
B. Rectangular Coordinates – Baseline
1. The simplest form of the rectangular coordinate system
2. Using a straight line between two known points, items are
measured along the line and then measured perpendicular to
the line
3. Inside or outside of a house, this line can be a straight wall
4. For outdoor scenes, use a string or a long measuring tape as
the reference or baseline
C. Rectangular Coordinates – Grid
1. Measure the distance of the items from two perpendicular
base lines
2. This technique is particularly appropriate in a room with
perpendicular walls or in the outdoors with perpendicular
streets
D. Polar Coordinates
1. Measure both the distance and the direction (angle) an object
is from a known reference point
2. For example, 40 feet from the edge of the house and 15
degrees east of north
VII. Search the Crime Scene
A. When searching a crime scene wear the following, if available, to
minimize contamination
1. Disposable gloves
2. Masks
3. Coveralls with a hood
4. Slippers
B. Search Patterns
1. Depend on the size and the location of the crime scene and
the number of investigators available
2. Stick to one pattern and one supervisor
3. It’s better to collect everything and not need it than fail to
collect something and need it later
4. Spiral – may move inward or outward; best used where there
are no physical barriers
5. Grid – basically a double-line search; effective, but timeconsuming
6. Line (Strip) – best in large, outdoor scenes
7. Zone (Quadrant) – most effective in houses or buildings;
teams are assigned small zones for searching
VIII. Collect and Package Evidence
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A. Physical evidence must be packaged and collected before time
and weather can alter it
B. Physical evidence – any object that can establish that a crime has
been committed or links a crime and the victim or suspect
C. The Golden Hour – the window of opportunity to collect timesensitive information or evidence
D. Each item must be placed in a separate container, and sealed and
labeled
E. The most fragile evidence is collected and packaged first
F. Different types of evidence require specific or special collection
and packaging techniques
G. The body is the property of the coroner or medical examiner;
collection of evidence on the body is done by that department
H. Containers such as vials, envelopes, plastic bags, paper bags,
canisters, and cardboard boxes are good packaging devices
I. Most items should be placed in a primary container and then in a
secondary container
J. Trace evidence may be placed on a piece of paper which is then
folded in a “druggist fold” and placed in a secondary container
K. Containers should be sealed with tamper proof tape, and dated
and initialed
L. Each package should contain
1. Date, time, and location
2. Case number
3. Agency and collector’s name
4. Victim’s name(s)
5. Description of contents
M. Never package two items from two different sources or locations
IX. Chain of Custody
A. There must be a written record of all of the people who have had
possession of an item of evidence, beginning at the time of the
collection
B. Every person who has handled or examined the evidence must be
accounted for
C. Chain of Custody should include
1. Date and time of transfer
2. Location of transfer
3. To/From names
4. Purpose of the transfer
X.
National Databases
A. Crime scene investigators can submit evidence for analysis to
several national databases depending on the type of evidence
B. Examples include
1. Automated Fingerprint Identification System (AFIS)
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2. Integrated Automated Fingerprint Identification System (IAFIS)
3. Combined DNA Index System (CODIS)
4. Integrated Ballistics Identification System (IBIS)
5. International Forensic Automotive Paint Data Query (PDQ)
Activities
1. Room Sketch. For homework, have students pick a room in their house
and make a rough sketch of the room. They will bring it back to class and
discuss how they decided what to include in their sketch and relate that to
a crime scene. Students will then make a final sketch from their rough
sketch. Use the Crime Scene Sketch Rubric to assess the final sketch.
2. Mock Crime Scene Investigation. Students will enter a mock crime scene.
They will work as a team to investigate the crime scene. Each student will
have a specific responsibility assigned to them by the team. Use the
Mock Crime Scene Investigation Responsibilities handout. Using all of the
team’s information, each student will submit a final sketch of the crime
scene and form a hypothesis about what happened. Use the Mock Crime
Scene Investigation Handout, the Data Table, and the Mock Crime Scene
Investigation Post Lab Questions for the activity. Use the Individual Work
Rubric for assessment.
Teacher note: You will need to set up a mock crime scene the day before
the activity (see the materials list for Activity 2). You will need to decide
what evidence and weapons will be included. Step-by-step student
instructions are found in the Mock Crime Scene Investigation Handout.
3. Crime Scene Investigation Review. Students will research and answer
the questions on the Crime Scene Investigation Review. The students
may work as individuals or in small groups. Use the Crime Scene
Investigation Review for the activity and the Crime Scene Investigation
Review Key for the assessment.
Assessments
Crime Scene Investigation Quiz and Key
Crime Scene Investigation Review Key
Crime Scene Sketch Rubric
Discussion Rubric
Individual Work Rubric
Research Rubric
Materials
Crime Scene Investigation computer-based presentation
Room Sketch Activity
– Paper
– Pen/ Pencil
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– Ruler
Mock Crime Scene Activity
– Room for a Mock Crime Scene
– Materials to set up as crime scene evidence (plastic weapons, table,
chairs, etc.)
– Paper or poster board
– Black pens and pencils
– Clipboard
– Rulers
– Compass
– Tape measure
– Camera
– Latex gloves
– Crime scene tape
– Crime scene badge (optional)
– Mock Crime Scene Investigation Handout
– Data Table
– Mock Crime Scene Investigation Post Lab Questions
– Mock Crime Scene Investigation Responsibilities Handout
Crime Scene Investigation Review and Key
Resources
0135158494, Saferstein, Richard. Forensic Science: An Introduction. New
Jersey: Pearson Prentice Hall, 2008.
0757518257, Ball-Deslich, Barbara and John Funkhouser. Forensic Science
for High School. 2nd Edition. Kenall/Hunt, 2009.
Accommodations for Learning Differences
For reinforcement, students will be given a rough sketch and produce a final
sketch from looking at the rough sketch. Use the Crime Scene Sketch
Rubric for assessment.
For enrichment, students will research a case where the crime scene was
compromised. Examples include the OJ Simpson, JonBenét Ramsey, and
Enrique Camarena cases. Use the Research Rubric for assessment.
State Education Standards
Texas Essential Knowledge and Skills for Career and Technical Education
§130.295. Forensic Science (One Credit).
(1)
The student, for at least 40% of instructional time, conducts
laboratory and field investigations using safe, environmentally
appropriate, and ethical practices. These investigations must
involve actively obtaining and analyzing data with physical
equipment, but may also involve experimentation in a
simulated environment as well as field observations that
extend beyond the classroom. The student is expected to:
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(A)
(2)
(3)
(5)
demonstrate safe practices during laboratory and field
investigations; and
(B)
demonstrate an understanding of the use and
conservation of resources and the proper disposal or
recycling of materials.
The student uses scientific methods and equipment during
laboratory and field investigations. The student is expected to:
(F)
collect and organize qualitative and quantitative data
and make measurements with accuracy and precision
using tools such as calculators, spreadsheet software,
data-collecting probes, computers, standard laboratory
glassware, microscopes, various prepared slides,
stereoscopes, metric rulers, electronic balances, gel
electrophoresis apparatuses, micropipettors, hand
lenses, Celsius thermometers, hot plates, lab notebooks
or journals, timing devices, cameras, Petri dishes, lab
incubators, meter sticks, and models, diagrams, or
samples of biological specimens or structures;
(G)
analyze, evaluate, make inferences, and predict trends
from data; and
(H)
communicate valid conclusions supported by the data
through methods such as lab reports, labeled drawings,
graphic organizers, journals, summaries, oral reports,
and technology-based reports.
The student uses critical thinking, scientific reasoning, and
problem solving to make informed decisions within and outside
the classroom. The student is expected to:
(A)
in all fields of science, analyze, evaluate, and critique
scientific explanations by using empirical evidence,
logical reasoning, and experimental and observational
testing, including examining all sides of scientific
evidence of those scientific explanations, so as to
encourage critical thinking by the student;
(B)
communicate and apply scientific information extracted
from various sources such as current events, news
reports, published journal articles, and marketing
materials;
(C)
draw inferences based on data related to promotional
materials for products and services;
(D)
evaluate the impact of scientific research on society and
the environment;
(E)
evaluate models according to their limitations in
representing biological objects or events; and
(F)
research and describe the history of science and
contributions of scientists.
The student recognizes the procedures of evidence collection
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(6)
while maintaining the integrity of a crime scene. The student is
expected to:
(A)
analyze the role of scientists such as forensic
pathologists and anthropologists as they relate to a
homicide investigation;
(B)
demonstrate the ability to work as a member of a team;
(C)
conduct a systematic search of a simulated crime scene
for physical evidence following crime scene protocol;
(D)
apply knowledge of the elements of criminal law that
guide search and seizure of persons, property, and
evidence;
(E)
describe the elements of a crime scene sketch such as
measurements, compass directions, scale of proportion,
legend, key, and title;
(F)
develop a crime scene sketch using triangulation,
rectangular coordinates, straight-line methods, and use
of coordinates on transecting baseline;
(G)
outline the chain of custody procedure for evidence
discovered in a crime scene;
(H)
demonstrate proper techniques for collecting and
packaging physical evidence found at a crime scene;
(I)
explain the functions of national databases available to
forensic scientists; and
(J)
collect and preserve physical evidence from a simulated
crime scene.
The student analyzes the evidence collected from a crime
scene using scientific methods. The student is expected to:
(A)
demonstrate conversions of measurements between
English and International System (SI) of units;
College and Career Readiness Standards
Science Standards
I. Nature of Science: Scientific Ways of Learning and Thinking
C. Collaborative and safe working practices
1. Collaborate on joint projects.
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Name________________________________ Date__________________________
Crime Scene Sketch Checklist
Objectives
Possible Points
Sketch is neatly completed
5
Sketch is drawn to scale
5
Evidence is labeled
5
North is labeled
5
Objects in drawing are proportional
5
Based on a rough sketch
5
Legend is complete
5
All fixed points are labeled
5
Length and width of the room are
labeled
5
Total Points
45
Points Earned
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Mock Crime Scene Investigation
Background Information
Thursday, Sept. 23, 8pm
There was a disturbance reported to 911. When the police arrived, there were signs of a
struggle and what appears to be blood in the room. There were no persons found at the scene.
Materials
Pencil
Paper
Clipboard
Tape measure
Compass
Ruler
Camera
Procedure Day 1: Investigate and create a rough sketch
1) Decide on team responsibilities and record them on the Mock Crime Scene Investigation
Responsibilities handout. Turn this in to your teacher.
2) Accompany your team to the crime scene room.
3) Decide on a search pattern and give each person a responsibility.
4) Identify all of the items that you believe are physical evidence. Make sure you note the
victim’s taped outline.
5) The team’s designated photographer should begin taking pictures of the crime scene.
Remember to get pictures of all of the entrances and exits: close-ups and wide-angles.
6) Record the locations of the physical evidence for your rough sketch.
 Use the tape measure to determine the width and length of the room
 Use the compass to determine north, south, east, and west walls
 Select fixed points for each piece of evidence and then measure in centimeters the
distance from your physical evidence objects to each fixed point. Record the
information in the data table. Repeat for each piece of evidence. You do not have
to use the same fixed points for every piece of evidence
7) Using the measurements, physical evidence, and notes, begin a rough sketch (at least 2
members of the team should be responsible for doing a rough sketch to give an accurate
picture).
8) The rough sketch should include
 The room number where the crime occurred
 Labeled north
 Doors and windows
 Representations of objects with squares or circles. Make the objects in proportion
to their size (a couch should be a larger square than a chair)
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

Each piece of evidence lettered or numbered. Make a key that lists each letter or
number and what it identifies
Dashed lines from your fixed points to your physical evidence. Write the actual
distance above the dashed line
Procedure Day 2
1) Using the rough sketch as a guide, draw a final sketch. The final sketch should be
polished so as to use it as evidence at a trial
2) Your final sketch should
 Be neatly drawn in black ink
 Be drawn to scale (Ex: 1 centimeter= 20 centimeters in the room). Include the
scale on your drawing
 Label north
 Represent the pieces of physical evidence in proportion with each other
 Label the physical evidence.
 Contain all of the measurements of distance from fixed points to the evidence
 Label the actual width and length of the room
 Include a legend containing your physical evidence identification
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Data Table
Physical
Evidence
Example:
spilled coffee
cup
Fixed Point #1
Example:
North door
Distance of
physical
evidence to
fixed point 1
Example:
115 cm
Distance of
physical
evidence to
fixed point 2
Fixed Point #2
Example:
Corner where
the west wall
meets the
north wall
Example:
250 cm
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Name________________________________ Date__________________________
Mock Crime Scene Investigation Post Lab Questions
1) What possible weapons were found at the crime scene? Where were they located?
2) Did anything seem to be out of place? What conclusions could you make about this?
3) What is the purpose of using fixed points?
4) Along with the background information and your notes, describe what you believe
happened.
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Mock Crime Scene Investigation Responsibilities
TEAM ___
Supervisor
_____________________________________
Photographer
_____________________________________
Sketch Artists (2)
_____________________________________
_____________________________________
Note-taker
_____________________________________
Marking and Measuring Evidence (2)
_____________________________________
_____________________________________
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Name________________________________ Date__________________________
Crime Scene Investigation Review
Answer the following questions on a separate sheet of paper.
1) What are the 5 steps in crime scene investigation?
2) Who should certify that the body is “dead”?
3) What does observing a crime scene involve?
4) What should a crime scene sketch include?
5) How do you measure at a crime scene?
6) What can be considered a fix point?
7) What are the 4 search patterns for crime scenes?
8) How do you decide which pattern to use?
9) When photographing a crime scene what are the important aspects to remember?
10) What is the Golden Hour?
11) How do you package evidence at a crime scene?
12) What is chain of custody? Why is it important?
13) How do you scale a sketch?
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Crime Scene Investigation Review Key
1) Isolate and secure the scene
Document the scene
Search for evidence
Collect and package evidence, maintaining the chain of custody
Submit evidence for analysis
2) Medical Examiner
3) Initial walkthrough
Plan of action
4) Date, time, location, scale, recovered items, fixed point distances, compass, legend
5) From two fixed points
6) Wall, door, window
7) Grid, Quadrant or zone, spiral, line or strip
8) Based on size, location and number of investigators
9) Photograph from all angles
Take wide angles and close ups
Do not move any evidence
Use a ruler to show scale
Photograph the area surrounding the crime scene
10) The window of opportunity to collect time-sensitive information and evidence
11) Individually packaged, no wet objects, new packaging
12) A record of the possession of evidence so we know who has come in contact with it
13) Example: Room is 600 cm by 610 cm
Scale is 1cm=40cm
Divide both measurements by 40 cm to get your scale drawing
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Name________________________________ Date__________________________
Crime Scene Investigation Quiz
Multiple Choice (10 points each)
_____1) Observing a crime scene involves what two things?
a) Initial walkthrough and plan of action
b) Walkthrough and search pattern
c) Collecting evidence and taking notes
d) Sketching the crime scene and photography
_____2) Who should certify that a body is “dead” at a crime scene?
a) First officer on scene
b) Medical examiner
c) Lead CSI investigator
d) Paramedic
_____3) The key to taking notes is what?
a) The legend
b) Scale
c) Shorthand
d) Details
_____4) All of the following would be considered fixed points except
a) Door
b) Wall
c) Desk
d) Window
_____5) The window of opportunity to collect time-sensitive information or evidence is known as
a) The Golden Hour
b) Immediate Response
c) Locard’s Exchange Hour
d) Chain of Custody
_____6) When packaging the evidence, you should
a) Package all like evidence together
b) Package only one piece of evidence at a time
c) Package everything from the crime scene together
d) Package it after you take it to the crime lab
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Short Answer( 10 pts each)
7) What are the 5 steps of crime scene investigation?
8) What is the responsibility of the first officer on the scene?
9) When an investigator documents a crime scene, what should they include?
10) Describe the four search patterns that could be used to search a crime scene.
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Crime Scene Investigation Quiz Key
1)
2)
3)
4)
5)
6)
7)
A
B
D
C
A
B
Isolate and secure the scene
Document the scene
Search for evidence
Collect and package evidence, maintaining the chain of custody
Submit evidence for analysis
8) A – Assess the crime scene and assist the injured
D – Detain the witness(es)
A – Arrest the perpetrator
P – Protect the crime scene
T – Take notes
9) Notes, Photography, Sketches, and Videography
10) Spiral – may move inward or outward; best used where there are no physical barriers
Grid – basically a double-line search; effective, but time-consuming
Line (Strip) – best in large, outdoor scenes
Zone (Quadrant) – most effective in houses or buildings; teams are assigned small
zones for searching
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Name_______________________________________
Date_______________________________
Discussion Rubric
Objectives
4 pts.
Excellent
3 pts.
Good
2 pts. Needs Some
Improvement
1 pt. Needs Much
Improvement
N/A
Pts.
Participates in group discussion
Encourages others to join the
conversation
Keeps the discussion progressing
to achieve goals
Shares thoughts actively while
offering helpful recommendations to
others
Gives credit to others for their ideas
Respects the opinions of others
Involves others by asking questions
or requesting input
Expresses thoughts and ideas
clearly and effectively
Total Points (32 pts.)
Comments:
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Name______________________________________
Date_______________________________________
Individual Work Rubric
4 pts.
Excellent
Objectives
3 pts.
Good
2 pts. Needs Some
Improvement
1 pt. Needs Much
Improvement
N/A
Pts.
Follows directions
Student completed the work as directed,
following the directions given, in order and to the
level of quality indicated
Time management
Student used time wisely and remained on task
100% of the time
Organization
Student kept notes and materials in a neat,
legible, and organized manner. Information was
readily retrieved
Evidence of learning
Student documented information in his or her
own words and can accurately answer questions
related to the information retrieved
*Research/Gathering information (if relevant)
Student used a variety of methods and sources
to gather information. Student took notes while
gathering information
Total Points (20 pts.)
Comments:
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Name______________________________________
Date_______________________________________
Research Rubric
4 pts.
Excellent
Objectives
3 pts.
Good
2 pts. Needs Some
Improvement
1 pt. Needs Much
Improvement
N/A
Pts.
Question/goal
Student identified and communicated a question
or goal of the research
Research/Gathering information (if relevant)
Student used a variety of methods and sources
to gather information. Student took notes while
gathering information
Conclusion/Summary
Student drew insightful conclusions and
observations from the information gathered.
Information is organized in a logical manner
Communication
Student communicated the information gathered
and summary or conclusions persuasively.
Student demonstrated skill in the use of media
used to communicate the results of research
Reflection
Student reflected on the importance of the
research and its potential application
Total Points (20 pts.)
Comments:
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