Name: ______Date: ______Period: _____

Bloodstain Pattern Analysis Lab

Objective: To create and interpret bloodstain patterns.

Materials: Simulated blood, paper, water dropper, straw, glove, various objects to create patterns, magnifier, and ruler

Procedure (Day 1):

1)Students will form groups of 3 people and write their names and period on the paper.

2)Tape the paper to the fencing, making sure that it is taut.

3)Create projected and impression patterns, including:

  1. expirated pattern
  2. cast-off pattern
  3. arterial spurting
  4. swipe
  5. wipe

Label each pattern type and indicate the materials used!

4)Untape the paper from the fencing and place it on the concrete.

5)Create passive, impression, and artifactual patterns, including:

  1. drip pattern – make sure to create plenty of satellite patterns
  2. transfer pattern
  3. wipe
  4. void

Label each pattern type and indicate the materials used!

6)Finally, while the paper is still flat on the ground, release a single drop of blood from the following heights. Use the meter stick to measure the heights.

  1. 10 cm
  2. 50 cm
  3. 1 m
  4. 2 m

Label each pattern!

7)Once finished, place all materials back into the tray and show the bloodstain patterns to Mrs. Boys

Questions for Day 1:

1)What patterns also created a flow pattern? What was the force that made this happen?

2)What kind of impression pattern would create skeletonized blood?

3)From part 6, how do the size and appearance of the blood droplets seem to vary with height?

Procedure (Day 2):

1)Students will reform their groups of 3 people and lay paper out on a cleared table.

2)Using the ruler and magnifier, complete the chart below. See image below for what to measure.

Distance of Fall (cm) / Drop Length (mm) / Drop Width (mm) / General Shape of Drop
10 cm
50 cm
100 cm (1 m)
200 cm (2 m)

3)Determine angle of impact of some the bloodstains from the cast-off pattern. On your bloodstained paper from yesterday, circle and number four bloodstains. Normally, you would divide the width by length, and then convert to an angle.

Example: Width: 2.2= 0.2716 angle = 15.76o

Length:8.1

Today, use to calculate the angle. Because you have measured the Opposite and Hypotenuse side, you will have to change the Dropdown to read “I want to calculate Angle & Adjacent Side.” Impute your measurements, and copy the Angle  = as your angle (not the Angle  = (90-) =)!

Bloodstain # / Width (smaller number) / Length (larger number) / Angle