Happy Friday! We are taking notes today. You will need lined paper and a pen or pencil. Title the notes Intro to Evidence

Introduction to Evidence

Target 1-3 I can characterize evidence by classifying its type and analysis plan.

Types of Evidence Biological Evidence Chemical Evidence Ballistic Evidence Physical Evidence

Biological Evidence Biological Evidence = any evidence that used to be part of a human body Ex) Blood Ex) Skin cells Ex) A dead body

Biological Evidence Analyzing biological evidence: Test for DNA Test for blood type Test for drugs and poisons Comparison analysis (match DNA or blood type to a suspect)

Chemical Evidence Chemical Evidence = any evidence that is unknown and must be identified or measured Ex) an unknown powder Ex) food or drink Ex) fire residue

Chemical Evidence Analyzing chemical evidence: Qualitative analysis: identifying the substance Quantitative analysis: measuring the amount of the substance Comparison analysis: match the substance to another substance

Ballistic Evidence Ballistic Evidence = any evidence that is related to firearms Ex) a gun Ex) bullets or shell casings Ex) bulletholes or bullet wounds

Ballistic Evidence Analyzing ballistic evidence: Striation analysis: use scratches to match a bullet to a gun Trajectory analysis: use math to determine where a gun was fired Test for gunshot residue to see who fired a gun

Physical Evidence Physical Evidence = any evidence that was transferred from one person/place to another Ex) fingerprints and shoe prints Ex) hairs, fibers, and soil Ex) paint, glass, or trace chemicals Ex) weapons

Physical Evidence Analyzing physical evidence: Microscopic analysis: use a microscope to identify or describe it Comparison analysis: match evidence from two places/people Test objects for fingerprints and DNA

Which is it? Fingerprint Bloodstain Some blades of grass A blue smear on the floor A gun A dead body

Which is it? 7. A knife 8. Muddy footprints 9. A glass with some liquid in it 10. Some broken glass 11. A few hairs 12. A few red threads

Now that we have evidence… Microscopic Analysis Qualitative Analysis Comparison Analysis Striation Analysis Quantitative Analysis Trajectory Analysis Toxicology (Drug) Test

In your groups… Which of the four types of evidence do you think is MOST useful? Explain why. Can you think of a single object that could be classified as ALL 4 types of evidence? Explain.