Blood Forensics

In order to test if a stain is blood or not, you must purchase expensive scientific equipment.

• True

• False

Answer explanation

Remember, I said you could purchase the "pee sticks" from any pharmacy section or Amazon.

When testing the fabric samples for blood, you were also performing a blood type test.

• True

• False

Answer explanation

No, the test for blood where you placed the Hemastix on the stain was very different from the blood typing test we did with the wet blood and Eldon card.

How many different alleles are there for blood type (this does not include the rH factor)? Think about the blood type test we did in class or the video I made.

• 1

• 2

• 3

• 4

Answer explanation

Alleles are the different variations of a gene, a genotype is the combination of the allele you get from your mother and the one you get from your father. Each could donate ab A, B, or O- thus, 3 alleles.

You can use the same Hemastix to test multiple stains for blood.

• True

• False

Answer explanation

That would lead to cross contamination.

When testing a piece of evidence, it is important to keep the piece of evidence with the evidence number.

• True

• False

Answer explanation

The evidence number helps determine when and where it was found- if you mix up the pieces of evidence it would have to be dismissed in court.

Challenging question: Which piece of evidence tested positive for blood?

• 000524-40: One (1) men's dress shirt, white, size M, with reddish stains

• 000524-49: One (1) t-shirt, white, size M, with reddish stains

• 000524-50: One (1) sweatshirt, hooded, blue, with Ole Miss logo, size XL, with dark stains

• 000524-41: One (1) pair ladies' trousers, gray, size S, with reddish stains

Answer explanation

The evidence number is labeled on the bag and the evidence inventory includes the number and description. The case solution folder also tells you the evidence number that tested possible for blood.

What blood type is this?

• B+

• A+

• O+

• AB-

What blood type is this?

• A-

• O+

• O-

• B+

Tags

NGSS.HS-LS3-2

Who was the criminal?

• Roger Hammond

• Maureen Kirby

• Steve Kirby

• Jonah Dale

Both the blood testing and the blood type testing involve chemical reactions.

• True

• False