BLOOD SPATTER
WHY IS IT IMPORTANT?
LESSON PLAN FOR BOE
JAN PETERSON HAMILTON HIGH SCHOOL
Blood Spatter, Why is it Important?
Chemistry Class, 10th -12th graders
Forensic Science Unit
Preview
The class period before we do this Lab students will be given an article to
read entitled The Forensics of Blood written by Brian Rohrig for Chem
Matters , February 2008. This will give them a basic insight into what the
lab will cover and get them excited about doing the lab.
Main Idea
Blood is an important source of information when found at a crime scene.
It can reveal information about it’s donor, and the patterns left can
determine how the crime was committed and help to develop a picture of
the crime scene.
Objectives
SWBAT identify how blood was deposited based on experimental
evidence.
SWBAT determine the height of the source of the blood based on their
experimental evidence
SWBAT determine the angle from which the blood was dropped based on
experimental evidence.
Opener
When students enter the classroom they will be met with blood spatter all
over the floor, and there will be a question on the board asking them to
list the ways that blood at a crime scene can provide information.
This will be followed by a brief discussion and a brain storming session to
list the ideas they come up with.
Lecture
The students will watch a power point presentation outlining why blood
evidence is important. This section of the lesson is made up of 4
individual lab activities where the students actually make blood spatter.
After each section teacher will Check For Understanding (CFU) with
random calling on students, and sharing with a partner to double check
ideas.
Experiments
Lab #1
Students use dropper bottles filled with fake blood to test
the patterns made from different heights.
CFU
Quick quiz questions.
Teacher CFU check with random students
Lab #2
This lab is experimentation to see how drops behave when
they land on top of one another.
CFU
Quick quiz review questions
Teacher CFU Check with random students
Lab#3
CFU
This lab explores how motion affects the drops. Students
drop blood on paper from slow, normal and fast walking
speeds, then analyze the results.
Quick quiz to review
Teacher CFU Random check with students
Lab#4
This activity explores the idea of how the angle that the
blood hits the paper affects the shape of the drops.
Students drop blood from predetermined angles to observe
how the drops are affected.
CFU
Quick quiz reviewing concepts of entire lab.
Teacher CFU
Discussion of lab with students and teacher calling on
random students.
During these activities teacher will move around class giving assistance
where it is needed.
Assessment
There will be two assessments for this lab. One will be the write up for
the lab and another will be the assigned the next class period. Teacher will have
a crime scene description and the students will work with a partner to determine
what evidence they can collect from the blood left at the scene. They will do this
using the information they gained from the labs, and write a complete report
explaining their conclusions.
Resources
Article
www.acs.org/chemmatters
Lesson
www.sciencespot.net/pages/classforsci.html#blood