FS Fall Final Review

Ch 1 and 2 observations and CSI Forensic investigators recognize, document, collect, and organize evidence left at the scene of a crime. Factors that affect observational skills such as emotion, perception and recall,time of day, level of interest, number of people… DOCUMENT DOCUMENT DOCUMENT

How does your brain work?

Your brain… Filters (what is important, what you notice, your level of interest, who you are with, where you are….) Fills in gaps (D yo kno wht I mn?) Applies previous knowledge –connect with what you know so it makes sense

Direct vs Indirect

Class vs Individual Blood Shoe impression Fingerprint DNA Physical evidence left at crime scene-gun, knife, rope, tape Race Gender

Physical Evidence

Trace

Who does what? Who secures the scene and separates witnesses? Who takes measurements and notes location of evidence? Who interviews the witnesses? Specialists?

First Find, then

Why secure the scene?

Identify the regions of hair

What part of the hair is shown?

DNA?

Human or NON-human Cuticle?

Consistent? Dissimilar? Inconclusive?

Is Hair CLASS or INDIVIDUAL evidence?

Medulla

Locard Every contact leaves a trace Duration Intensity Materials used

Control?

Fingerprint Minutiae

Fingerprints arches, loops and whorlsarches, loops and whorls Principles of FingerprintsPrinciples of Fingerprints 1. unique 1. unique 2. unchanging 2. unchanging 3. can be used to ID individuals 3. can be used to ID individuals

Kinds of Crime Scene Prints Patent /Visible prints –Patent /Visible prints – –made by fingers touching a surface after ridges have been in contact with a colored materials (blood, paint, etc.) Plastic Prints –Plastic Prints – –ridge impressions left on a soft material (putty, wax, soap or dust) Latent/invisible prints –Latent/invisible prints – –caused by the transfer of perspiration/oils on finger ridges to the surface of an object

Identify each fingerprint pattern. Right Hand Left Hand Right Hand

How can we use these?

What Can be learned from tire impressions? What type of impression is shown?

What can you learn from studying the gait (walking pattern)

What can we learn?

Why is Chain of Custody so important?

Class vs Individual