Forensics- Ch. 2 The Crime Scene

Locard's Exchange

This principle states that whenever 2 objects come in contact with one another, a cross-transfer of physical evidence can occur

intensity, duration, nature of the crime

The three factors affect the amount of evidence transferred during a crime

direct

Firsthand observations such as eyewitness account, videos, confessions are classified as this type of evidence

circumstantial

Indirect evidence that can be used to imply a fact but does not directly prove it

physical

Synthetic fibers, weapons, bullets, shell casings, paint chips, documents, imprints and prints (shoes, tires, etc), toolmarks, soil, and drugs are considered this type of circumstantial evidence

biological

Bodies or body parts, body fluids, hair, leaves or other plant parts, natural fibers, feathers, and wood are considered this type of circumstantial evidence

trace

Evidence which consists of small but measurable amounts of physical or biological material

class

This type of evidence narrows down the suspects to a group of persons or things

individual

This type of evidence narrows down the suspects to a single person or thing

district attorney

The elected or appointed official who represents the government in the prosecution of criminal offenses

first responding police officer

Whose duty is it to make sure the scene is secure by first making sure all individuals in the area are safe and second by preserving evidence?

prevent contamination

Reason why members of the crime scene investigation team must all wear protective gear (gloves, etc.)

prevent them from forming a collusion

Reason why members of the crime scene investigation team must separate witnesses at a crime scene

Innocence Project

A non-profit legal organization that is committed to exonerating wrongly convicted people through the use of DNA testing

eyewitness misidentification

The single greatest cause of wrongful convictions nationwide

DNA

In 75% of their cases, the Innocence Project has been able to free individuals from prison for wrongful convictions using this type of evidence

primary

The crime scene where the crime actually occurred

secondary

A crime scene that is in some way related to the crime but is not where the actual crime took place

photography

This crime scene unit takes pictures of the overall area and close up photos with and without a measuring ruler

north

An arrow should be drawn on a crime scene sketch to show this direction

forceps

This tweezer-like tool should be used to pick up small evidence to prevent contamination

arson

Evidence remaining from this type of crime need to be stored in airtight, unbreakable containers

mold

Bloodstained materials must be packaged in wrapping paper, manila envelopes, or paper bags to prevent the growth of this on the evidence

paper bindle

A way of folding paper to hold small evidence; also known as a druggist's fold

signature of the collector

What needs to be written across the tape of an evidence container?

chain of custody

A list of all persons who came into possession of an item of evidence

admissible

Term for acceptable or valid evidence used in a court of law

control

These types of samples should be taken from the victim for purposes of exclusion

standard

Term for reference samples obtained from the victim, family members, any paramedics/police officers who may have been in the crime scene, suspects, and other known sources; also used for purposes of exclusion

buccal

Term used to describe a cheek swab to collect cells for comparison with evidence

lead detective

This individual receives the lab results after evidence has been tested by the crime lab

homicide

Initially all death investigations should be treated as this type of crime

4th

Any removal of evidence from a crime scene must be in accordance with this Amendment

search warrant

A legal document authorizing a police officer or other official to enter and examine a home or business

make sure all individuals are safe, preserve evidence

The two most important factors when securing a crime scene

Secure the scene, Separate the witnesses, Scan the scene, See the scene, Sketch the scene, Search for evidence, Secure and collect evidence

seven S's of crime scene investigation

spiral

Name this pattern used to search for evidence

grid

Name this pattern used to search for evidence

linear

Name this pattern used to search for evidence

quadrant or zone

Name this pattern used to search for evidence

homicide

All death investigations should initially be treated as this type of crime

4th

Any removal of evidence from a crime scene must be in accordance with this Amendment

double-blind procedure

When the person administering a suspect line-up does not know who the suspect is and makes sure to tell the victim they do not know who the suspect is

under emergency circumstances, if there is immediate danger of the loss or destruction of evidence, if there is probable cause — the search of a person and their immediate property in conjunction with a lawful arrest, or with the consent of the involved parties

circumstances in which a crime scene can be searched without a warrant

A photo of the evidence in relation to the overall crime scene (location), close-up of evidence with a ruler, and close-up of evidence without a ruler

When photographing a piece of evidence at the crime scene, list the three ways it should be photographed