Forensic Blood Case Studies

Name:

Date:

🔍 Part 1: Case Study Analysis

Case Study 1: The Missing Backpack

A student's backpack was stolen from the school library. Security cameras show someone leaving through the back exit, but the person's face isn't visible. However, investigators found small drops of blood on the door handle where the person exited. The blood appears fresh and red in colour.

1. What could the blood evidence tell forensic scientists about this case?

The exact time the theft occurred

The identity of the person through DNA analysis

How much money was in the backpack

The weather conditions that day

2. Which safety considerations should investigators follow when collecting this blood evidence? (Select all that apply)

Wear protective gloves

Use sterile collection tools

Take photographs before collecting

Collect samples with bare hands for better grip

Case Study 2: The Broken Window

A shop window was broken during the night. Glass fragments are scattered on both sides of the window. Blood drops are found on some glass pieces inside the shop, and there's a trail of blood drops leading away from the scene for about 10 metres before disappearing.

3. What can investigators determine from the blood drop patterns?

The direction the person was moving

The person's favourite colour

What the person stole

The person's age

4. The blood appears bright red and hasn't clotted yet. What does this suggest about when the incident occurred?

🧬 Part 2: Investigative Questions

Case Study 3: The Laboratory Accident

In a school science laboratory, a student accidentally cut their finger while cleaning glassware. The teacher needs to clean up the blood safely and determine if the cut requires medical attention. There are several small drops of blood on the bench and one larger spot where the student initially bled.

5. Develop two investigable questions that could help determine the severity of the cut based on the blood evidence:

Question A: _________________________________________________

Question B: _________________________________________________

6. Which component of blood is responsible for clotting, and why is this important in forensic investigations?

7. Explain one ethical consideration that forensic scientists must follow when collecting and analysing blood samples:

🔬 Part 3: Planning Your Investigation

Case Study 4: The Sports Equipment Mystery

After a football match, the team's expensive equipment bag goes missing from the change rooms. The next morning, a small amount of blood is found on the door frame of the equipment storage room. The blood has darkened overnight and begun to clot.

8. Choose one aspect of this blood evidence to investigate and plan your approach:

My investigable question: ________________________________________

What data would I collect?

What safety measures would I take?

9. How has the blood's appearance changed from being fresh to overnight, and what causes this change?