Forensics Unit 1- Intro to Forensics (CSI Investigation, History, and Types of Evidence)

What three things must a forensic examiner be able to do?

1. find (identify the evidence)

2. document (the evidence)

3. interpret (the evidence)

How is information processed in the brain?

Information from our senses - what we pay attention to - perception - short term memory - long term memory

what are some variables that can impact the accuracy of a persons observation?

Stress, concentration, amount and kind of distractions present, any lapse of time since the event

What is the purpose of the Innocence Project?

to re-examine post conviction cases, used DNA to prove innocence in cases where a person was wrongfully convicted based on faulty eyewitness testimonies

Define and give examples of circumstantial evidence.

Evidence that relies on an inference to connect to the crime scene. Examples: fibers from a shirt, blood type, hair, photos (these examples all link a person to the crime scene, but inference is needed to connect the evidence to the crime)

Define and give an example of Locard's Exchange Principle.

Whenever 2 objects come in contact with one another, a cross-transfer of physical evidence can occur. The intensity, duration, and nature of the materials in contact determine the extent of the transfer.

Where does evidence that is collected at a crime scene go?

forensic laboratory and or the crime lab

Frye Standard

the evidence in question must be "generally accepted" by the scientific community

Daubert Ruling

provides a rule of evidence regarding the admissibility of expert witnesses' testimony during United States federal legal proceedings.

Difference between the Frye Standard and the Daubert Ruling

Frye focuses on whether the expert testimony is accepted by the scientific community, Daubert broadened the approach and offers a list of factors to consider before expert testimony is accepted into court, not just based on the acceptance of the scientific community. In Daubert it is up to the judge on whether the expert testimony is admissible in court.

Who is the "gate keeper" for evidence during a trial according to the Frye standard?

the scientific community

Whos is the "gate keeper" for evidence during a trial according to the Daubert standard?

the judge

Define and give examples of direct evidence

Evidence that directly links a person to a crime (no need for inference) examples: witness testimony, video, confessions

Define class evidence

material that connects an individual or thing to a certain group

define individual evidence

a kind of evidence that identifies a particular person or thing

Compare and contrast individual and class evidence

- Class evidence: evidence that narrows down the suspect pool to a group of people. Examples: blood type, types of clothes, shoe prints, hair sample, physical description ( all of these help narrow down the suspect pool, but does not directly link the evidence to a suspect)

- Individual Evidence: evidence that narrows down the suspect pool to a single individual, anything that can be linked to a unique, single, specific source. Examples: nuclear DNA, fingerprints, tool marks

What are the reasons you can search a person's home?

If you have a warrant, with consent, exigent circumstances (someone is in danger, or hurt)

What is the definition of Forensic Science?

the application of science to law

What two types of law make up forensic science?

criminal and civil law

Define trace evidence

Evidence that can be transferred from person to person or place to place (leaves a trace) examples: soil, fibers, hair, glass

List the 7 S's of crime scene investigation

- Secure the scene

- Separate the witnesses

- Scan the scene

- See the scene

- Sketch the scene

- Search for evidence

- Secure the evidence

List the responsibilities of the responding officers to a crime scene.

- Obtain medical assistance If needed

- Arrest suspects

- Isolate the area

- Request additional needs for investigation

What is the difference between a misdemeanor and a felony?

- Misdemeanor: less serious than felonies, penalties include less than a year in jail, community service, fines

- Felonies: more serious crimes, penalties include at least a year in prison, losing your right to vote

List 4 results of the "CSI Effect"

- More people interested in forensic science

- Unreasonable expectations of evidence (more DNA)

- Unreasonable expectations of how quickly the evidence is processed (jurors think DNA evidence can be processed in 45 minutes)

- Depictions of technologies that do not exist

- What crime scene investigators and forensic scientists do

When are Miranda Rights read to an individual and must they be from memory?

- They must be read when the suspect is in police custody, and subject to an interrogation. It is actually better if the cop reads off the Miranda card, then there is no room for error on the cops side.

What should you include in a crime scene sketch?

- North should be labeled, all important objects (weapons and body) should be measured from two immovable objects

- All other objects in the vicinity should be included

- Date, time, location, case number, names of who sketched and verified sketch

List a few other disciplines that forensics relies on

- Chemistry, biology, physics, psychology, criminalistics, anthropology, pathology, toxicology, odontology, entomology, ballistics, engineering

What is the chain of custody?

documentation or paper trail showing custody, control, transfer and analysis of everyone who comes in contact with the specimens

Why is the chain of custody important?

In order to present credible evidence in court

List the steps to package an evidence bindle (think sock lab)

- put on gloves

- observe the evidence

- complete your druggist fold

- place evidence in your druggist fold

- fold your druggist fold and make sure it is sealed

- label your druggist fold with your name and case number

- bag evidence

- add identification

- seal it

- sign across the sealed edge

- sign evidence log (chain of custody)

List all the steps to photograph a crime scene.

- Seeing the Scene (7 S's)

o Overview photos: allows investigators to see the evidence in relation to the entire scene

o Mid-range shot: allows investigators to see the evidence and other objects nearby in detail

o Close up- with scale (ruler and evidence marker): must be taken at a 90-degree angle (directly above)

o Close up without scale: to make sure no evidence is hiding underneath the marker and ruler

o Play with the lighting: sometimes evidence can be seen only if you look at it in a different way (oblique lighting)

Alphonse Bertillon

Father of criminal identification

Sir Edward Henry

He devised a workable classification system for fingerprints

Karl Landsteiner

Developed modern classification of blood types

Edward Locard

said that "every contact leaves a trace" also began the world's first crime lab in France

Locard's Exchange Principle

Whenever two objects come into contact with one another, there is exchange of materials between them.

Calvin Goddard

Invented the comparison microscope

Rosalind Franklin

Used X-ray diffraction to discover the double-helical structure of DNA.

Watson and Crick

Developed the double helix model of DNA.

Alec Jeffreys

invented DNA fingerprinting

Zone Search Method

Used on crime scenes that are comprised of readily definable zones, such as in houses or buildings. Teams are assigned small zones for searching, and then other appropriate searching methods are employed in each zone.

Spiral search pattern

a search pattern often used outside by one person in which the searcher begins at a certain point and walks in increasingly larger circles to the outmost boundary of the search area.

Line Search Method

Used on large, outdoor crime scenes. Members of the search team are arranged at regular intervals, usually arm's length, and then proceed to search along straight lines.

Grid search pattern

Two or more investigators form a grid by searching in line patterns that overlap and are perpendicular to each other. (big open areas)

Biological Evidence

body fluids, hair, plant parts, natural fibers

primary crime scene

the location where the crime took place

secondary crime scene

a location other than the primary crime scene, but that is in some way related to the crime, where evidence is found

Transient Evidence

temporary; easily changed or lost; usually observed by the first officer at the scene