Forensics Honors Unit 2 Study guide yay

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List the seven S’s of Crime scene investigation

Securing the scene, separating the witnesses, scan the scene, see the scene, sketching the scene, searching for evidence, and securing and collecting evidence

What items are required on a crime scene sketch

North should be labeled with a scale of distance measured from 2 immovable land marks, any other objects in vicinity included such as doors or windows, and labels–date, time, location, case number, names (sketched/verified by__)

What is Locard’s exchange principle

Every contact leaves a trace

What three factors determine the extent of the transfer of forensic evidence

intensity, duration, nature

Give three examples of direct evidence

(first hand observations) eyewitnesses, videos, confessions

What is circumstantial evidence? Describe each of the three categories of circumstantial evidence

(Indirect evidence used to imply a fact but not directly prove it) physical (fibers, weapons, bullets), biological (body/body parts, body fluids, hair), trace evidence (hair, dna, drop of blood, fingerprints) REMEMBER THEY CAN BE MORE THAN ONE CATEGORY

Define and give an example of class evidence

Narrows evidence to group of people or things (type of weapon, blood type)

Define and give an example of individual evidence

Narrows evidence to a single person or thing (Fingerprints, handwriting, DNA, physical matches sometimes)

Why is evidence so important in forensics? List the five reasons

Can prove crime committed and set scene for investigation, can back witness testimony or prove false, can link suspect with victim or crime scene, can determine the identity of people associated with crime, and it allows investigators to reconstruct the scene

(PIRATES BEWARE, LEGAL INVESTIGATORS ROAM)

Who is responsible for securing the crime scene

Police officer

What are two priorities while securing the crime scene

Must ensure no evidence is lost and make sure all individuals in area are safe

Why is it important to separate any witnesses at a crime scene

Witnesses must be separated to prevent them from working together and create a story (Collusion)

What is the purpose of the innocence project

Reexamine post conviction cases by overturning (typically mis identification due to eye witness testimonies) using DNA testing

What is the difference between primary and secondary crime scene

primary crime scene is where crime actually occurred; secondary crime scene is related to the crime but not directly where it occurred.

What should be included in crime scene photos

overview, close ups at 90 degree angle, pictures with and without evidence number and ruler, midrange photo with two important items in the scene next to each other for reference, oblique lighting using uv or other colored filter lights

What should be included in crime scene sketches (5)

Date, time, location, case number, and names (labeled as “sketched and verified by..) [also label north, Any important objects such as weapons or the body are measured from 2 immovable landmarks, any other objects in vicinity such as doors or windows]

List and sketch the four methods to search a crime scene

spiral, grid, line search method, quadrant or zone method

Describe the various containers used to collect evidence and what kind of evidence each can hold

blood in manilla paper folders, liquid in leakproof containers, arson evidence in clean air-tight metal cans, dried blood in druggist fold,

What information is included on evidence log (7 thingds)

evidence descriptions, evidence inventory number, case number, date of recovery, the time of recovery, location of recovery, and who the evidence was recovered by. It may also include signatures of the witnesses present during the collection.

What information is included in the chain of custody

The chain of custody includes who received the piece of evidence, who had the piece of evidence, the date, and the time.

Why are evidence logs and chain of custody so important for evidence collection

The evidence log is important to prevent the evidence from being deemed as “inadmissible” or unusable in court. Plus, the evidence lacking a chain of custody will have less weight in court. It makes sure that no piece of evidence has been tampered with.

Where should forensic detectives get control samples from? What are control samples used for

It’s taken from victims for exclusion such as blood or hair. A standard reference sample is physical evidence from suspect that can be compared to crime scene. Blood stained evidence such as whole blood from veins or buccal from cheeks can be obtained.

What are some signs that a crime scene was staged

Evidence being moved, weapon being found in strange place, cleaning agent used, signs of extra or unnecessary damage

Which amendment affects crime scene investigation? Explain how it affects an investigation

The 4th amendment requires a warrant for any evidence collected at the scene.

When can a crime scene be searched without a warrant

probable cause, permissions from subjects to conduct a search, immediate danger of the loss of evidence, or under emergencies (danger to life or limbs)