blo od spatte r Program overview to explain bloodstains

FSB01
blo od spatte r
Program overview
Using the laws of physics
to explain bloodstains
in forensic evidence.
Blood spatter: suggested lesson plan.
The program is designed to enable students to
participate in a range of activities that require them
to make observations, collect, analyse and interpret
data and try to form a conclusion.
A scenario is included that drives the program
however the program is flexible so it can be used in
ways that suit you and your classroom.
You may choose to introduce the online “crime
scene” at the start of the program or you may
leave the crime scene as a culminating activity.
The suggested activity sequence is with the online
crime scene at the conclusion of the program.
It would be difficult to recreate the crime scene
in your own classroom however certain sections
could be created with care. The online crime scene
was recreated specifically for a WA Police Forensics
training program using porcine (pig) blood.
The program is organised into a series of pdf files.
• Background information for the teacher about
various aspects of the program has been included.
• Teacher activity information has been provided
for each activity with hints and technical notes.
• One PowerPoint presentation has
been included for download.
Session 1 – What is blood?
Why is it useful to solve crimes.
•FSB03, FSB04, FSB05
• Set the scene by showing some footage from
a movie or episode of CSI where someone
is injured resulting in blood spatter.
• Use this to generate discussion on the use
of blood to help solve crime. What do they
already know about blood spatter?
• Brainstorm ideas on what they already know
about blood and its physical properties.
Discussion of surface tension and why this is one of
the most important properties of blood that allow
forensics investigators to use blood spatter to solve
crime.
Session 2 – About blood spatter
•FSB10
• Talk about the blood spatter footage
shown yesterday. Let the students discuss
amongst themselves what they saw.
• Show the footage again and pause
it on the blood spatter.
• Ask the students to discuss what they could find
out from the blood spatter pattern to help work
out how the crime was done. Share the ideas
with the class and record them on the board.
• Show PowerPoint presentation (FSB10) of
different types of blood spatter (passive,
transfer, projected, dripped, spilled, projected,
arterial spurt, cast off, impact spatter.
• Computer-based resources include a crime
scene and three statements about the crime: a
suspect, a witness and a victim. Students use
their knowledge gained from the program to
decide what statement fits the evidence.
• Ask the students to discuss how
each type is created.
• Student worksheets are divided between a
Personal Dossier and a Crime Dossier. Both
documents can be printed to form two separate
booklets that students work from, or you may
choose to print and use only specific activities.
• Create some hypotheses.
• Brainstorm other things that might cause the
size and shape of a blood spatter to change.
Conduct an experiment to find out how the angle
of impact affects blood droplet patterns.
FSB01
blo od spatte r
Program overview
Session 3 – The relationship between
height and bloodstain diameter
• Activity 1: FSB06, FSB07, FSB08
• Conduct an experiment to find out how
drop size and shape changes with height.
Session 4 – Influence of surface texture
• Activity 3: FSB06, FSB07, FSB08
• Conduct an experiment to find out how
the type of surface changes the size
and appearance of a bloodstains.
• (Compare surfaces such as glass, lino,
carpet, wood, concrete and grass.)
Session 5 - Determining the direction
of travel from a blood droplet pattern
Activity 4: FSB06, FSB07, FSB08
• Conduct an experiment to find out how you
can determine the direction a blood droplet
came from. and therefore the angle of impact.
Session 9 – Determining the area of origin
• Activity 7: FSB06, FSB07, FSB08
• Students receive a pattern of bloodstains
that has been created by a different group of
students. Using skills and techniques developed
throughout the program they attempt to
determine the area of origin of the bloodstains.
Session 10 – Scenario
• Activity 8: FSB07, FSB09, FSB11
• Given a scenario and using the knowledge
they have gained over the last few lessons
students try to reconstruct a crime scene
using blood splatter (need to keep records
of each experiment piece together
Session 11 – What happened?
• Sharing reconstructions and re-enacting
what they think happened.
• Students present their evidence.
Session 6 – How does the angle of
impact affect blood droplets?
• Activity 2: FSB06, FSB07, FSB08
• Conduct an experiment to find out how the
angle of impact affects blood droplet patterns.
Session 7 – Calculate the angle of impact
• Activity 5: FSB06, FSB07, FSB08
• Use the results from Activity 4 to calculate the
angle of impact of various blood droplets.
Session 8 – The effect of
velocity on bloodstains
• Activity 6: FSB06, FSB07, FSB08
• Do a demonstration or conduct an experiment
to assess the effect that changing the amount
of force has on the resulting bloodstains.
FSB01
blo od spatte r
MODULE OVERVIEW Using the laws of physics to explain bloodstains in forensic evidence.
Science
Outcomes
Lesson Outline & Activities
Assessment
Resources
FSB03 What is forensic science
Introduction and setting the scene.
What is forensic science?
FSB03 Suggested episodes CSI
How is blood used as evidence.
FSB04 About blood
Physical properties of blood.
FSB05 Properties of blood
About blood spatter
FSB03 Suggested episodes CSI
Discussions of previous CSI footage.
FSB10 Blood spatter PowerPoint
PowerPoint presentation.
Activity 1
The relationship between the bloodstain
diameter and dropping height.
Activity 2
The effect of different receiving surfaces
on bloodstains.
Activity 3
Methods used to determine the direction
of blood droplets.
Activity 4
The effect of the angle of impact on the
appearance of the blood spatter pattern.
Activity 5
Calculation of the angle of impact
Activity 6
The effect of velocity on bloodstains.
Investigating scientifically:
developing a hypothesis,
identification of variables, results
and conclusion writing.
FSB07 Height and bloodstain activity.
FSB008 Student Dossier
Investigating scientifically:
designing own experiment
(hypothesis, variables, methods,
results and conclusion)
FSB05 Surface and bloodstain
information.
Investigating scientifically:
designing own experiment
(hypothesis, variables, methods,
results and conclusion)
FSB05 Direction of bloodstains
information.
Investigating scientifically:
designing own experiment
(hypothesis, variables, methods,
results and conclusion)
FSB05 Angle of impact information.
Investigating scientifically:
designing own experiment
(hypothesis, variables, methods,
results and conclusion)
Energy and Change: explanation
of why droplets change with
speed using the ideas of energy
and force.
Activity 7
Determining the origin of the blood.
FSB05 Height and bloodstain
information.
Investigating scientifically:
designing own experiment
(hypothesis, variables, methods,
results and conclusion)
FSB07 Surface and bloodstain activity.
FSB08 Student Dossier
FSB07 Direction of bloodstains activity.
FSBS08 Student Dossier
FSB07 Angle of impact activity.
FSB08 Student Dossier
FSB05 Velocity and bloodstains
information.
FSB07 Velocity and bloodstains activity.
FSB08 Student Dossier
FSB05 Area of origin calculations
information
FSB07 Area of origin calculations
activity.
FSB08 Student Dossier
Students will
problem solve
and apply their
understandings to
solving the crime.
Activity 8
The online scenario of the crime scene.
Students will investigate the crime scene
to try and determine “who did it”.
Energy and Change: scientific
ideas used in explanation of how
the crime was committed.
FSB07 Scenario information.
Communicating scientifically:
sharing results with rest of class in
an oral presentation.
FSB09 Crime File
FSB11 Scenario activity.
FSB09 Crime Dossier.
This involves reconstructing “what
happened” on the basis of the bloodstain
pattern.
Students may need to conduct more
experiments themselves to determine
what the spatter pattern is saying.
Students will
communicate
ideas with other
class members.
Activity 9
Sharing reconstructions and re-enacting
what they think happened.