blood spatter worksheets

HP MODEL #2
Worksheet #1 : Blood Spatter Evidence
Name___________________________________________________ Class Period____________
Teacher________________________
Throughout this project we will examine the shapes, locations, and distribution patterns of
bloodstains. This will help provide us with an interpretation of the physical events that occurred at a
crime scene. Medicolegal Investigators (MI’s) are responsible for being educated, trained, and
proficient in evaluating such situations at crime scenes.
1.) Use the blood spatter evidence given to you to determine the blood drop size. Record your
measurements on the table below. (3 points)
Drop Distance (m) Drop Diameter (mm)
0.5
1.0
1.5
2.0
2.5
3.0
2.) Plot the results on the graph below. The drop distance will be your independent variable (“x”) and
your blood drop diameter will be dependent (“y”). (6 points)
OVER

3.) Using the regression capabilities of your graphing calculator : (5 points)
a.) Find a linear regression to model the data. (If needed, round values to the nearest hundredth.)
RECALL: Stat Edit
Stat Calc - #4
b.) Sketch and label this regression on your graph.
4.) . . . use your regression model and the diameter of the
blood drop from the power point to determine the height of where his wound originated.
(1 point)
HP MODEL #2

Worksheet #2 : Blood Spatter Article Review
Name___________________________________________________ Class Period____________
Teacher________________________
Article by : J. Slemko Forensic Consulting
Read through the given information sheet and answer the following questions.
1.) On average, blood volume accounts for what percent of a person’s total body weight? (1 point)
2.) What percent of blood volume loss is required for death to occur? (1 point)
3.) The surface tension of blood tends to form a _______________________ shape rather than a
teardrop shape when free falling or projected. (1 point)
4.) Name the 3 categories of bloodstains. Give examples and characteristics of each. (6 points)
OVER
0
5.) Explain the shape of a droplet of blood that strikes a surface at an angle less than90
. (1 point)

6.) State the Trig formula used to determine the angle of impact (AOI). (1 point)
7.) Explain how the point of convergence (origin) is determined with several bloodstains. (Feel free to
use a diagram to help with your explanation). (3 points)
HP Model #2 - Blood Spatter

HP Model #2 - Blood Spatter
Excerpts from an article by : J. Slemko Forensic Consulting

HP MODEL #2
Worksheet #3 : Blood Spatter Lab Analysis

Name___________________________________________________ Class Period____________
Teacher________________________
1.) Use the blood spatter evidence collected from the lab to fill in the Angle Data Table below. (9 points)
Impact Angle Sketch Diameter (W) Length (L) (W/L)
10°
20°
30°
40°
OVER

Impact Angle Sketch Diameter Length (W/L)
50°
60°
70°
80°
90°

W
The Trig formula used to determine the angle of impact (AOI) is sinθ
= .
L
Where θ =the angle, W = width of the bloodstain, L = length of the bloodstain.
1
This indicates the AOI can be found by sin W − ⎛ ⎞
⎜ ⎟=
θ .
⎝ L ⎠
2.) Choose 4 angles from the data collected and justify the Trig relationship. (4 points)
(Be sure your calculator is in degree mode!)
OVER

3.) Plot the results of the lab on the graph below. The angle measure will be the “x” variable
and your W ⎛ ⎞
⎜ ⎟ ratio will be the “y” variable. (6 points)
⎝ L ⎠
4.) Using the regression capabilities of your graphing calculator : (5 points)
a.) Find a linear regression to model the data. (If needed, round values to the nearest hundredth.)
RECALL: Stat Edit
Stat Calc - #4
b.) Sketch and label this regression on your graph.