Forensic Science exam 1 -- BSU

What is forensic science?

The application of science to criminal and civil law

American Academy of Forensic Sciences (AAFIS) Sections

Criminalists, Digital & Multimedia Sciences, Engineering Science, General, Jurisprudence, Odontology, Pathology/Biology, Physical Anthropology, Psychiatry/Behavioral Science, Questioned Documents, Toxicology

Locard's Exchange Principle

When two objects come into contact with each other a cross-transfer of materials occurs

IAFIS

Integrated Automated Fingerprint Identification System

NGI

Next Generation Identification

CODIS

Combined DNA Index System

NIBIN

National Integrated Ballistics Information Network

PDQ

Paint Data Query

What can be said to explain the rapid growth of crime labs during the last forty years?

Supreme Court decisions in the 1960s, staggering increase of crime rates in the U.S., and the advent DNA profiling

Is there a national forensic lab system?

No

Basic Services of Forensics Lab

Physical Science Unit, Biology Unit, Firearms Unit, Documentation Examination Unit, Photography Unit

Optional Services of Forensics Lab

Toxicology, Latent fingerprint, Polygraph, Voiceprint Analysis, CSI, Psychiatry, Odontology, Engineering, Computer & Digital Analysis

Functions of a Forensic Scientist

Analysis of physical evidence, provide expert testimony, provide training for police and other CJ professionals

What is the first step in securing a crime scene?

Establish boundary, Exclude unauthorized personnel, Medical assistance for individuals in need

What is the second step in securing a crime scene?

Preserve and protect area, try not to disturb evidence, record victim statements,

What is the third step in securing a crime scene?

Call for backup/investigative personnel

What are the walk through points of a scene?

Initial survey, establish entry & exit, document obvious items associated with incident, place numbered markers, document absence of items on scene, answer/document important questions

What is a primary scene?

Location where initial offense was committed

What is a secondary scene?

Locations of all subsequent connected events

What are tasks that need to be assigned on a scene?

Locating, processing, and assessing of evidence, photographing the scene, sketching/mapping the scene

Line Search

Work horizontally across an area with large groups of volunteers

Grid Search

Basically a double-line search; effective, but time-consuming

Spiral Seach

Searchers work in a spiral

Wheel/Ray Search

Searchers start at a center and move outward along straight lines or rays

Quadrant Search

Effective for INDOOR and OUTDOOR scenes that have regular patterns or DEFINED BORDERS.

Vehicle Search Steps

Avoid contact with surfaces, look for potential cross-body transfer, search inside & outside of vehicle

What are ways you can record a crime scene?

Hand-written notes, Voice recording, taking photos, sketching scene

Film Photography

uses light-sensitive celluloid, and processed with chemicals

Digital Photography

the use of electronic means to capture light and save an image on a microchip

DSLR Cameras

A digital single-lens reflex camera

What are the different types of lenses used on a crime scene?

Wide angle, telephoto, macro, zoom, fisheye, and normal

Video Documentation

The act of videoing a crime scene and verbally documenting the scene either during the recording or after

Crime Scene Sketching

The act of drawing out the crime scene and including all elements that are important to the scene

Packaging and Procedure for biological evidence

Air-dry and use paper bags with biohazard sticker

Chain of Custody

The documented list of all people who handled a piece of evidence and what time they handled it

Standard/Reference samples

Physical evidence whose origin is known, such as blood or hair from a suspect, that can be compared to crime-scene evidence

Substrate Samples

A clean sample of a surface near a stain at a crime scene (ex. unstained piece of carpet, fabric, etc.)

Personal Protective Equipment/Gear

Equipment worn to minimize exposure to hazards, including gloves, masks, and goggles.

Legal Considerations

Factors that must be taken into account regarding the law and regulations during an investigation or forensic analysis.

Fourth Amendment

Protects citizens from unreasonable searches and seizures, requiring law enforcement to obtain a warrant based on probable cause.

What is scene reconstruction based on?

Observation and evaluation of physical evidence

What is the purpose of scene reconstruction?

To help determine theories on the chain of events that a crime happened

Objectivity

Based on inductive reasoning, deductive reasoning, and falsifiability

Inductive Reasoning

drawing conclusions from a premises one does not know are correct

Deductive Reasoning

drawing conclusions based on known facts or premises

falsifiablity

Ability to prove a hypothesis wrong.

Bifurcation

When trying to apply a simple yes/no answer to a complex question there is not always a clear cut solution or conclusion

Generalization

making an assumption of truth using broad generalizations about nature of evidence

False Linkage

a connection between 2+ pieces of evidence is assumed and leads down the wrong path

Evidence used in scene reconstruction

Direct physical evidence, circumstantial evidence, testimonial evidence, reenactments

Theory Formation

Information should fit into the overall picture, reconstruction should only include definitive events, and you need to use sequencing

Timeline Charts

A timeline chart is a reconstruction of the crime-scene that shows the series of events in which they are assumed to have happened according to witness testimony and any kind of survalence around

The number of pixels contained in a digital camera is directly related to the detail and sharpness of the image, which is called its what?

Resolution

A minimum of how many feet should be photographed in a tire impression?

Eight feet

What do CAD programs enhance the ability of?

Finishing a crime-scene sketch

Photographs of what kind of evidence require a camera designed to create a 1:1 photograph or by a standard camera fitted with an adapter?

Latent fingerprint evidence

Whenever possible, the evidence submitted to the laboratory should be...?

Intact

Identification

Determines physical or chemical identity of a substance

Comparison

Analysis subjects a suspect specimen to a standard

Individual Characteristics

Properties of evidence that can be attributed to a particular source with an extremely high degree of certainty

Class Characteristics

Properties of evidence that can associated only with a group and not a single source

Product Rule

Formula for determining how frequently a certain characteristic occurs in a population

Value of Evidence

Value hinges on the ability to corroborate events with data in a manner that is as free from human error and bias as possible

Rapid DNA

a process for developing DNA profiles from a buccal swab

Forensic Palynology

The use of pollen and spores in criminal investigations

Pollen spores

Consist of both male and female gametes of plants like algae, fungi, mosses, and ferns