Unit 2 Slides for Survey of Forensic Science

Corpus Delicti

Body of the Crime

that a crime occurred and that the person charged with the crime was responsible for it

must be proven

Top reasons for committing a crime

• money

• investigator

• revenge

Crime scene team

a group of professional investigators, each trained in a variety of special disciplines

Team members

• first police officer on the scene

• medics (if necessary)

• investigator(s)

• medical examiner (if necessary) or representative from office

• photographer and/or Field evidence technician

• lab experts

Logic and forensic techniques involve

• recognition

• identification

• individualization

• reconstruction

recognition

scene survey, documentation, collection

identification

comparison testing

individualization

evaluation and interpretation

reconstruction

reporting and presenting

Evidence

• body

• primary crime scene

• secondary crime scene

• suspect(s) and their property

first officer on the scene must

ADAPT

ADAPT

assess the crime scene

ADAPT

detain the witness

ADAPT

arrest the perpetrator

ADAPT

protect the crime scene

ADAPT

take notes — compile data, including preserving any fragile evidence at the scene

Basic police department structure

PITA

PITA

Patrol Division

PITA

Investigate Division

PITA

Tactical or S.W.A.T.

PITA

Administrative division/training

Medicolgeal death investigator

representative from the medical examiner or coroner’s office

Police investigators

ideally 5 respond to a scene

jurisdiction

police have __________ of the crime scene

Lead investigator

responsible for the crime scene

document

Case detectives ________ the crime scene

investigate

Case detectives _________ the original or reporting patrol officer.

examine

Case detectives _______ the crime scene with csi

pass

Case detectives ____ necessary info to assisting detectives

assign

Homicide supervisors _____ roles

arrange

Homicide supervisors _____ resources

keep

Homicide supervisors ____ assignment logs

relay

Homicide supervisors _____ info to commanders

confirm, announce

Medicolegal death investigators _______ and ________ death

photograph

Medicolegal death investigators __________ scene and body

identify

Medicolegal death investigators ________ deceased if possible

document, evaluate

Medicolegal death investigators ________ (with sketch) and ________ body

rigor mortis, liver mortis, body temp, position

Medicolegal death investigators document _____

trauma and/or unusual markings

Medicolegal death investigators record ______

on or around the body

Medicolegal death investigators collect evidence __ __ ______ ___ ____

reconstruct

Medicolegal death investigators _______ death event

jurisdiction

Medicolegal death investigators maintain _______ over body

conveyance

Medicolegal death investigators insure safe _______ of body to morgue

family

Medicolegal death investigators assist _______

Walk through

Performed by the crime scene investigator, the first officer and sometimes the lead detective

Crime Scene Team’s purpose (1)

to mentally prepare a reconstruction theory

transient or conditional evidence that could change, weather conditions

Crime Scene Team’s purpose to take notes of

Crime Scene Team’s purpose (2)

Record initial observations (who, what, where, when, how)

Crime Scene Team’s purpose (3)

Identify special needs for personnel, precautions, or equipment; notify superior officers or other agencies

Notes

date and time, description of the location, weather and environmental conditions, description of the crime, location of the evidence relative to other key points, the names of all people involved, any modification that have occurred and other relevant information

Photographs

photos of scene and surroundings, mid-range to close-up photos with various angles of each piece of evidence, photos as viewed by any witnesses. Careful to document.

Sketches

inclusion of date, time, scale, reference points, distance measurements, names of investigators, victims suspects, and a legend (key)

Videography

allowed narration (non-subjective) to be included

Crime scene sketch

Establishes a permanent record of items, conditions, and distance and size relationships

Crime scene sketch (2)

Supplement photographs

Crime scene sketch (3)

Number designations should coordinate with the evidence log number destinations

Crime scene sketch includes

• Case identifier

• Date, time, location

• Weather and lighting conditions

• Identity and assignments of personnel

• Dimensions of rooms, furniture, doors, and windows

• Distances between objects, persons, bodies, entrances, and exits

• Measurements showing the location of evidence

• Key, legend, compass orientation, scale, scale discoaimer or a combination of these features

How should the objects be organized when using measurements showing the location of evidence?

objects should be located by two measurements from non-movable items such as doors or walls

Link method

Based on the lineage theory of Locard, one type of evidence leads to another; experimental, logical and systemic; most common and productive type used

Line or strip method

Best in large, outdoor scenes

Grid method

Basically a double line search; effective, but time consuming

Zone method

Most effective in houses or buildings; teams are assigned small zones for searching

Wheel or ray method

Best on small, circular crime scenes

Spiral method

May move inward or outward; best used where there are no physical barriers

Triangulation mapping

Uses two points at the crime scene to map each piece of evidence

Coordinate or grid mapping

Divides the crime scene into squares for mapping

Suspend polar coordinate mapping

For use in mapping evidence in a hole

Baseline mapping

Set a north/south line and measures each piece of evidence from this line

Evidence collector ensures that the evidence is

Collected, packaged, marked, sealed and preserved in a consistent manner

Separate container, seals, and labeled

Evidence must be placed in a

Coroner, medical

The body is the property of the _______ or _______ examiner

Druggit’s fold

Used with larger pieces of paper folded around larger items to hold trace evidence in place

Chain of Custody

A written record of all people who have had possession of an item of evidence

Evidence container

Must be marked for identification

Collector’s initials

Should be placed on the seal

recorded

If evidence is turned over to another person, the transfer must be _______

Narcotics

Find illegal drugs

Tracking

Look for a fugitive or suspect who might be near the crime scene

Bomb detection

Look for explosive devices

Arson detection

Detect various types of accelerants

Search and rescue

Look for people who are lost

Cadaver

Detective decomposition

Human remains specialists

Can detect any human remains