Unit 1: Intro to forensic science

Discuss with your neighbor How do detectives use logic to help them narrow down to one suspect? (think about your Deadly picnic)

What are the rules of evidence? Probative value: proves something related to the case Most evidence collected at a scene has very little if any probative value Example, in the case of a motor vehicle accident, a witness's testimony that she saw one automobile enter the intersection on a red light is a probative fact about whether the driver was at fault. Material: evidence that addresses issue of crime

What makes up Physical Evidence? Transient: temporary, easily changed or lost Usually observed by the first officer on the scene Ex: odor, temperature, imprints or indentations, markings

Types of Physical Evidence Pattern or Transfer evidence- produced by direct contact between a person and an object or between two objects

Types of Physical Evidence Conditional- produced by a specific event or action Important in crime scene reconstruction Ex: lighting, smoke, location (stains, victim, vehicle, etc.) vehicles, body position, scene (condition of furniture, doors/windows) signs of disturbance

What is the difference between Individual evidence and class evidence? Object has characteristics common to a group of similar objects Not to a single object Individual evidence Can be linked to a unique, single, specific source

Ticket out the Door In your notebook, create a Venn diagram comparing individual and class evidence. 2 differences, at least 1 similarity