Forensics Exam

What is the medullary index of the hair shown below? The width of the hair shaft is 72 microns and the width of the medulla is 130 microns?

.18 Human

What is the medullary index of the hair shown below? The width of the medulla is 1 micron and the width of the hair shaft is 3 microns.

.5 Animal

Which classification of the medulla is this picture?

Absent

Why is hair mostly considered class evidence? -Hair can only indicate a racial group/sex/age; therefore, can only be matched to a class of individuals. -Without the follicle, it can't be linked to an individual. -Because its characteristics can be linked to a certain class of people. -All of the choices**

All of the choices

he body of a woman was found in the woods. Some hair fibers found on the body were sent to the crime lab for analysis. The ends of the hair attached to the body were gray but showed that it had been dyed. The distance from the root of the hair to the beginning of the dyed area measured 8 mm. Investigators determined that the victim's hair had last been dyed on August 1, 2004. Assuming the hair grows at a rate of 0.44 mm per day, approximately what date did the woman die? *

August 19, 2004

Which protein composes a strand of hair?

Keratin

Which famous person's hair analysis possibly determined that he died from a poison called arsenic?

Napoleon

Microscopic

Pigmentation of the cortex and Pattern of the medulla

Neutron activation analysis can check hair for the presence of?

Silver

Which famous person's hair analysis possibly determined that he died from a poison called arsenic?

true

What are the factors/formula used to calculate the medullary index?

width of the medulla / width of the hair

All hairs on the head of a person are identical

False

What part of the hair must be present in order to conduct a full DNA analysis?

Follicle

Of the following which is NOT part of the hair shaft ____

Follicle and oil gland

Which classification of the medulla is this picture? *

fragmented

The cuticle scales of the hair always point toward the

tip of the hair

Human hair grows at a rate of about 1.3 cm per month (approximately 0.44 mm per day). If the unbleached root region measured 2.5 cm from a suspect's dyed hair sample, approximately how many weeks ago did she dye her hair?

7 weeks

Transparent, contains the scales, protects

A

A woman with long hair is a suspect in a burglary case. At the crime scene, several long hairs were found attached to a broken lock of the safe. The police obtain a warrant and request a sample of 25 to 50 hairs from this woman. They tell the woman it is important that they pull the hairs from her head rather than to merely cut the hairs. The police suspect that the woman was stealing to help support a drug habit. Suppose the hairs of the woman match the hairs found at the crime scene. Why does this not necessarily prove that she was the guilty party?

Because of Locard's exchange principle. Hair is an example of trace evidence. If she was present at the scene, her hairs could have been left behind (such as getting attached to the safe's broken lock). So it does not necessarily mean that she broke into the safe, but was just present and her hairs were left behind. Further investigation will then have to be performed to ensure that she's the one responsible.

Largest part and contains the pigment.

C

A woman with long hair is a suspect in a burglary case. At the crime scene, several long hairs were found attached to a broken lock of the safe. The police obtained a warrant and requested a sample of 25 to 50 hairs from this woman. They tell the woman it is important that they pull the hairs from her head rather than to merely cut the hairs. The police suspect that the woman was stealing to help support a drug habit. The woman denies that she is currently taking drugs and states that she stopped using drugs a year ago. What statement below explains how the police can determine if the woman has been off drugs for over one year.

The police can test her hair shaft in order to check if there are drugs present. The chemicals absorbed by the skin also get taken in by hair. A solvent is used to break down the hair's keratin and substances in the hair are released. The timeline from when she may have taken the drugs or been exposed can be calculated using the rate of hair growth as well as where the toxin or drug is located from the hair root.

Hair is composed of a protein called keratin

True

The shaft of the hair is considered class evidence in a trial.

True

Macroscopic

color and curliness

Put the stages of hair in the correct order from oldest to youngest.

follicle dormant root has club appearance, slow growth & elongated root, actively produces the hair