INTRO TO FORENSIC SCIENCE

Chain of custody

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

Area of convergence

A two-dimensional plane from which the drops in an impact pattern originated

Which of the following is the best explanation for the increased number or growth in the number of crime labs in the United States?

All of the reasons listed have led to the growth in the crime lab in the U.S.

What contributor to forensic science is known as the father of criminal identification?

Alphonse Bertillon

Back spatter

Also known as blow-back spatter, is projected backward from the source

Forensic science is

An umbrella term that encompasses many different professions that use their skills to assist law enforcement in conducting investigations

Broadest definition of forensic science

Application of science to criminal and civil laws. "The application of science to law"

At the crime scene, the string method is used to find the _____ of an impact spatter pattern.

Area of origin

What individual is noted for the creation of the oldest forensic lab in the United States in 1923?

August Vollmer

What contributor to forensic science refined the techniques involved in determining whether a particular firearm was used in a crime or incident by comparing the physical evidence found at a crime scene with a round that was test-fired from the same firearm through the use of the comparison microscope?

Calvin Goddard

Arterial spray spatter

Caused by an injury to the heart or a main artery and the pressure of the continuing pumping

A list of all of the people who came into possession of an item of evidence from a crime scene is known as what? This is very important because it plays a vital role in court, in determining the authenticity and integrity of the evidence, and in determining if evidence will be considered admissible or not.

Chain of custody form

3 major avenues used to assist enforcement

Confessions, witness testimony, and physical evidence (lacks bias/error)

Expirated blood pattern

Created by blood that is expelled from the mouth or nose from an internal injury. Usually high velocity spatter due to being under pressure

Finished sketch

Created from the information in rough sketch, but is drawn to scale with care and concern for appearance

Cast off spatter

Created when a blood-covered object flings blood in an arc onto surface. Usually produced by fists or between blows

Void pattern

Created when an object blocks the deposition of blood spatter onto a target surface or object and the spatter is deposited onto the object or person instead

Contact/transfer pattern

Created when an object with blood on it touches one that does not have blood on it

Locard exchange theory

Cross transfer of evidence occurs

Leone Lattes

Developed procedure to determine blood type from dried bloodstains and used it as a way to id an individual

Albert Osborn

Document examination

Which of the following is considered a basic service provided by a full-service crime lab?

Document examination unit

Medium velocity spatter

Drop with diameters from 1-4 mm with an applied force of 5 to 25 ft/sec

Low velocity spatter

Drops with diameters of 4 mm or more normally produced by an applied force of up to 5 ft/sec.

High velocity spatter

Drops with diameters of less than 1 mm; applied force of 100 ft/sec or faster

Physical evidence

Encompasses any and all objects that can establish that a crime has or has not been committed or can provide a link between a crime and its victim or a crime and its perpetrator

Class Characteristics

Evidence associated only with a group is said to have class characteristics

Correct physical evidence collection procedure.

Evidence from an arson crime scene, especially that with fumes, should be packaged separately in airtight metal cans

Individual characteristics

Evidence that can be associated with a common source with an extremely high degree of probability -fingerprints-

Forward spatter is more likely to be deposited on the object or person creating the impact

False

Identification is the process of ascertaining whether two or more objects have a common origin

False

In comparing the terms forensic science and criminalistics. Criminalistics is an umbrella term used to encompass all of the many professions that use their skills to aid law enforcement officials in conducting their investigations, whereas forensic science is a term used for describing all of the many services of a crime lab.

False

Most items of physical evidence retrieved at crime scenes can be linked definitively to a single person or object

False

NIBIN is the FBI's complete DNA database that became fully operational in 1998

False

The necessity for the forensic scientist to appear in court is based on the 5th amendment, but comes from the 1993 Supreme court case, Daubert v Merrell Dow Inc.

False

The oldest forensic lab in the United States is that of the FBI.

False

When conducting a search at a crime scene the search for physical evidence should be superficial and disorganized.

False

Francis Galton

Fingerprints

Role of probability

Frequency of occurrence of an event

What crime scene search pattern is noted for needing two investigators to conduct line searches, is known as being through, but that the boundaries must be well established in order to use it well?

Gird search pattern

What contributor to forensic science wrote in 1893 the first written work that described how the application of the many different scientific disciplines could be utilized in criminal investigation? Basically he detailed how each of these scientific disciplines could be of assistance to the criminal investigator.

Hans Gross

Which of the following is a national fingerprint and criminal history system maintained by the FBI and launched in 1999?

IAFIS

There are two processes that forensic scientists undertake when examining physical evidence. Determine that an explosive mixture contains dynamite is an example of what process

Identification

The amount of spatter from a blood droplet falling on a hard, non-porous surface is ________ that of a drop of blood of equal size, falling from the same distance, onto a softer, porous surface.

Less than

An impact pattern consisting of large separate drops with diameters of 5 millimeters is:

Low velocity spatter

General bloodstain features

May uncover - direction from which blood originated, the angle at which a blood droplet struck a surface

Calvin Goddard

Microscope and examine particular gun fired

Walter McCrone

Microscopy

Pools of blood

Occurs when blood collects in a level and undisturbed place. Blood that pools on an absorbent surface may be absorbed throughout the surface and diffuse, creating a pattern larger than the original pool

The presence of a cast-off pattern shows that there were more than ________ blow(s) delivered:

One

Spiral search pattern

One investigators searches in a spiral path from the center of the crime scene to the boundary (outward) or from the boundary of the crime scene to the center (inward)

Identification

Purpose the determination of the physical or chemical identity of a substance with as near absolute certainty as existing analytical techniques will permit

The database that includes more than 300 manufacturers of shoes with more than 8,000 different sole patterns is the:

SICAR

Rough or porous surfaces usually result in stains with

Satellite spatter

The use of what provides a safety net to ensure that the outcome of an investigation is not tainted by human emotion or compromised by distorting, belittling, or ignoring contrary evidence?

Scientific method

The duty of the first officer on scene or the first responding officer is to do what?

Secure and isolate the crime scene

Drop trail pattern

Series of drops that are separate from other patterns, formed by blood dripping off an object or injury

The Frye standard

Set guidelines for determining the admissibility of scientific evidence in court

Wheel/ray search pattern

Several investigators search in straight lines from the center to the boundary (outward) or from the boundary to the center (inward)

Which crime scene search pattern usually employs one person and involves working the scene from the center toward the boundary or from the boundary to the center of the crime scene? This type of pattern is not always beneficial because evidence can be missed.

Spiral search pattern

Comparison analysis

Subjects a suspect specimen and a standard/reference specimen to the same tests and examinations for the ultimate purpose of determining whether or not they have a common origin

Quadrant/zone search pattern

The crime scene is divided into smaller sections (zones). One or more investigators are assigned to search each zone

There are two types of sketches that are completed by the crime-scene investigator. Which sketch is drawn away from the crime scene and is a precise rendering of the crime scene and is usually drawn to scale. This is done with concern of aesthetic appearance, must reflect the information from earlier renderings, and is done with the aid of computer-aided drafting software?

The finished sketch

Effects of surface texture

The harder and less porous the surface, the less spatter results

Once the scene is secured and isolated and the lead investigator arrives, the lead investigator begins evaluating the crime scene. One of the first things done by the lead investigator is what?

The initial walk-thru of the crime scene

crime scene reconstruction

The method used to support a likely sequence of events at a crime scene by the observation and evaluation of physical evidence and statements made by individuals involved with the incident

Impact bloodstain spatter pattern

The most common type of bloodstain pattern

A standard/referred sample is physical evidence whose origin is known and can be compared to crime scene evidence to either make a match and determine who the suspect might be or to remove someone form consideration in a criminal investigation.

True

Crime labs in this country to large extent mirror the law enforcement structure that exists on the national, state and local levels. That means that crime labs are fragmented jurisdictionally.

True

Once the first responding officer responds to the scene of the crime and secures and isolates the scene. A log should be kept of the dates and times that all authorized and unauthorized people enter and exit the scene of the crime. Obviously those that are unauthorized should not gain access.

True

Ridge characteristics of fingerprints, random striating markings on bullets or ammunition, and irregular and random patterns in ties or footwear impressions all exhibit individual characteristics

True

The jury ultimately determines the significance of physical evidence in a trial

True

Line/Strip search pattern

One or two investigators start at the boundary of the crime scene and search in straight lines across to the other side of the crime scene

Skeletonization

Phenomenon that occurs when the edges of a stain dry to the surface. Usually happens within 50 seconds of deposition of the droplets

There are three ways to document the crime scene. Which one is utilized the least due to the cost of it?

Photography

3 methods to record crime scene

Photography (4 minimum ranges), sketches, and notes

The phenomenon known as the CSI effect is that which results from the dramatization of forensic science on tv and it causing the public to believe that every crime scene will yield forensic evidence and the unrealistic expectation that every criminal case should be bolstered and supported by forensic science.

True

The pointed end of a bloodstain always faces it's direction of travel

True

This contributor to forensic science, Albert S. Osborn, did not make nay specific technical contribution to forensic science, but instead he demonstrated how the many different scientific disciplines could be incorporated within the workable crime lab.

True

When measured or mixed with extreme precision, no two items- even those originating from the same source - we exactly alike

True

When using photography as a way to document the crime scene, csi prefer DLSR cameras. When using DLSR cameras, the number of pixels featured in the camera, the better the resolution.

True

The intersection of straight lines through the long axis of several individual bloodstains in an impact spatter pattern illustrates the ________ of the pattern.

area of convergence

Mathieu Orfila

father of forensic toxicology, first scientific treatise on detecting poisons and their effects on animals

Gunshot spatter

fine forward spatter from an exit wound and back spatter from an entrance wound. The gunshot produces only back spatter if the bullet doesn't exit the body

The likelihood of finding class physical evidence is ________ the likelihood of finding physical evidence with individual characteristics.

greater than

A bloodstain that impacts a surface at a low angle will have a ______ tail than one that impacts at a higher angle

longer

Flow patterns

made by drops or large amounts of blood flowing by the pull of gravity

Multiplying together the frequencies of independently occurring factors is called the:

product rule

Forward spatter

projected outward and away from the source

Angle of impact formula

sin A=(width of blood stain/length of blood stain)

Area of origin

the area in a three-dimensional space from which the blood was projected

A comparison analysis subjects a suspect specimen and a control specimen to the same tests and examinations for the ultimate purpose of determining:

whether or not they have a common origin

Two techniques used to document bloodstain patterns

1. Grid method - A grid of squares of known dimensions are set up over the entire pattern 2. Perimeter ruler - A rectangular border of rules is set up around each pattern and a smaller ruler next to each stain