Forensic Science: Crime Scene, Hair, Glass, and Fingerprint Analysis

What should you do if an accident occurs in the lab?

Report it immediately

What does PPE stand for?

Personal Protective Equipment

Name three examples of PPE.

Gloves; goggles; lab coat

What is one basic lab safety rule?

No eating or drinking in the lab

What must be included on all crime scene sketches?

Title; case number; date/time; location; sketcher name; scale; legend; measurements; north arrow

What are the two main types of crime scene sketches?

Rough sketch; finished sketch

What is a rough sketch?

A sketch made at the crime scene

What is a finished sketch?

A clean, final version of the rough sketch

Name one crime scene sketching method.

Triangulation

What is the baseline method?

Measuring from a straight line reference

What is rectangular coordinate method?

Using perpendicular measurements from two fixed points

What is polar coordinate method?

Using angles and distances from a fixed point

What is an elevation sketch?

A vertical view showing walls or height details

What are the three main parts of hair?

Cuticle; cortex; medulla

What is the cuticle?

The outer layer of hair

What is the cortex?

The middle layer containing pigment

What is the medulla?

The inner core of the hair

What type of DNA is found in the hair root?

Nuclear DNA

What type of DNA is found in the hair shaft?

Mitochondrial DNA

How does human hair medulla compare to animal hair?

Human is thin/absent; animal is thick

What cuticle pattern do humans have?

Imbricate

What is the most common hair found at crime scenes?

Human head hair

What are the three main fiber types?

Natural; synthetic; man-made

Is rayon (viscose) natural or synthetic?

Man-made

Are fibers class or individual evidence?

Class evidence

What type of fracture forms first in glass?

Radial fracture

What type of fracture forms second in glass?

Concentric fracture

What do radial fractures look like?

Cracks radiating outward

What do concentric fractures look like?

Circular cracks

What is the most common type of glass?

Float glass

Name one type of glass.

Tempered glass

What is the purpose of the density procedure?

To compare glass samples

What is ballistics?

Study of projectile motion

What is firearm identification?

Matching bullets to a specific gun

What are lands?

Raised areas inside a barrel

What are grooves?

Indented areas inside a barrel

What do lands and grooves do?

Create markings on bullets

What are the three principles of fingerprint identification?

Unique; permanent; classifiable

Which skin layer produces fingerprints?

Dermis

What are the three fingerprint patterns?

Loop; whorl; arch

What is a loop fingerprint?

Ridges enter and exit the same side

What is a whorl fingerprint?

Circular or spiral pattern

What is an arch fingerprint?

Ridges flow from one side to the other

What skill is required for the practical section?

Using a microscope

What is a wet mount?

A slide prepared with liquid for viewing specimens

What should you focus on in hair under a microscope?

Medulla patterns