Forensics Unit 2

To recognise, document, and collect evidence at a crime scene as well as piece together evidence to form a picture of what happened at a crime scene

Statement made under oath/testimonial evidence

Narrows an identity to a single person or thing. This is found by either a unique combination of characteristics that could only belong to a person or thing Always involves a comparison

Any object or material relevant to a crime 1. physical evidence, 2. Locard’s exchange principle 3. class vs individual evidence

Narrows an identity to a group of persons or things

SMall but measurable amounts of physical or biological material found at a crime scene

blood, prints, fibers, hair, body fluids

Police/district attorney CSI Medical examiners detectives specialists

• Secure the scene • Separate the witnesses • Scan the Scene • See to it that crime scene examiners receive overall and close up photos with an without measuring rulers • Sketch the scene • Search for evidence • Secure the collected evidence

Responsibility: First responder 1st priority: Safety of individuals 2nd priority: Preserving evidence they establish a perimeter and keep track of people at the scene

Investigators compared witness notes

When did the crime occur Who called in the scene Who was the victim Can the perpetrador be identified What did you see happen Where were you when you observed the crime scene

Done by forensic examiners Determines where photos should be taken

Crime scene examiners need to see the scene they take tons of photos from wide to tight

Accurate rough sketch Note positions of body/evidence Objects should be measured from two immovable points North is labeled A more accurate sketch is made for court

A spiral, grid, linear, pattern should be walked and location of evidence marked, photographed and sketched Also oblique lighting needed

All evidence needs to be properly packaged, sealed, and labeled

Liquids and arson remains in an airtight container Biological evidence in a breathable contrainters to dry out Other evidence should be put in a paper bindle then in a bag/container It needs to be taped shut and signed by collector

Used to present credible evidence in court 1. a person bags evidence, marks it for identification, seals it and signed it across the sealed edge 2. Signed over to a technician in a lab for analysis who opens it but not on the sealed edge 3. After analysis the technician puts it back in the evidence bag, seals it in another bad and signs evidence log

Primary scene is where the crime is committed A second scene would be the home of the suspect

You need to form a hypothesis on the sequence of events from before the crime was committed through its commision

A bindle is a paper bag used for transporting and holding evidence

This makes it so that evidence is easier to see from the naked eye

Falsifiability- refers to testing new theories and methods (repeatable results are valid) Known error rates Peer review General Acceptance