Unit 1 Introduction

1A. Forensic Science is the study and application of science to legal matters.

1. Forensic comes from the Latin word forensis which means forum (where there was judicial hearings).

2. Forensics science = criminalistics

3. Forensic scientists study different types of evidence recovered from crime scenes.

a. Testify in court as an expert witness

i. Presents data, evaluates evidence and renders an impartial opinion

b. Performs scientific research and to train others.

4. The following are disciplines used in forensics

a. Chemistry

b. Biology

c. Firearms

d. Document examination

e. Photography

f. Toxicology study of poisons

g. Fingerprints

h. Polygraphy the study of lie detection

i. Pathology study of unexplained/unusual death

j. Anthropology study of human kind

k. Psychiatry study of mental disorders

l. Odontology study of teeth and dental records

m. Engineering

n. Computer technology

o. Geology study of the Earths structure

p. Environmental science

q. Entomology- study of insects

r. Physics

1B. The Legal System

1. There are several different types f law in the U.S. criminal justice system.

1. Statutory Law written law

a. The law on the books.

b. Made by congress.

c. Based on the Constitution

2. Civil Law deals with relationships between individuals

a. Marriage, divorce, wills, property, contracts

b. Assigns a blame

c. Needs a preponderance of evidence to convict

d. Punishable by fines (generally)

3. Criminal Law deals with offenses against and individual that are deemed offensive to society

a. State would bring charges against the accused.

b. Misdemeanor minor crimes like small thefts, minor assaults(threat of bodily harm)/battery (bodily harm), possession of small amounts of drugs.

c. Felony- major crimes like murder, armed robbery, dealing drugs

d. Needs to be deemed guilty beyond a reasonable doubt.

e. Punishable by fines, incarceration, community service, life in prison and capital punishment

4. Equity Law - remedial or preventative

a. Restraining orders or injunctions (orders to start doing something or to stop doing something)

5. Public Law regulation and enforcement of rights

6. Administrative Law I.R.S., social security administration, military

1C. The steps in pursuing justice.

2. Crime is committed

3. Crime discovered

4. Police investigate

5. Crime scene documented and searched for evidence

6. Information gathered and given to prosecutor

7. Arrest warrant is issued if there is enough evidence for probable cause. 5% of arrests are with warrents

8. Arrest, Maranda rights, fingerprinted, photographed

9. Preliminary hearing bail, pleas for misdemeanor, trial worthy

10. Trial date

a. 50% of those arrested are convicted

1. 25% of those convicted go to jail

11. Observation what a person perceives using his/her senses.

a. Investigators must observe interpret and report clearly.

b. To collect evidence without making judgements (until later)

c. Perception interpreting information received from the senses

1. It is not always accurate

People

1. Filter information

2. Fill in gaps

3. Apply previous knowledge

12. 2. Observation by witnesses

a. Eyewitness a person who has seen someone or something and can communicate the facts (info that can be verified).

b. Emotional statis influences our ability to observe

c. Other things that influence observational skills:

1. Whether the person in alone or in a group

2. The number of people or animals in the area

3. What type of activity was occurring in the area

4. How much activity was occurring

d. Eyewitness accounts of a crime scene vary considerably from one another due to: stress, interest, prejudices, personal beliefs, motives, memories fade and concentration

e. Eyewitnesses often give their opinions of what happened instead of the facts.

1. Opinion personal belief based on judgement rather than on direct knowledge

f. Eyewitness testimony is very powerful and can sway a jury.

g. Knowing the shortcomings of eyewitness testimony is necessary to ensure justice.

13. Police officers and investigators

a. Are trained to have good observational skills

b. Are trained to have good analytical skills

1. Ability to identify a problem

2. Isolate the component parts

3. Organize information

4. Establish criteria to evaluate

5. Draw appropriate conclusions

c. Are trained in deductive reasoning

1. Deductive reasoning deriving the consequences from the facts using a series of logical steps

1D. Evidence

1. Direct evidence evidence in the form of a statement made under oath

A. Physical evidence any object or material that is relevant in a crime scene

B. Locards principle there is always an exchange or transfer of material when two objects touch or come into contact.

C. Edmond Locard - 1877 1966 French scientist)

2. Indirect evidence evidence that does not prove a fact

A. Circumstantial evidence implies a fact or event.

1. The more circumstantial evidence, the higher probability of a crime.

3. Class evidence narrows an identity to a group of persons or things

A. Ex. Blood typing can narrow the lists of sustpects

4. Individualized evidence is evidence that can be traced back to a single source.

A. **The best evidence is the type to be individualized to a single specific source.

5. Good Evidence

A. Proves that a crime has been committed

B. Corroborates testimony

C. Links a suspect with a victim or crime scene

D. Establishes identity

E. Allows reconstruction of events of a crime

6. 1. The Rules of Evidence define what is acceptable (admissible) and how it can be used for the jury

A. Relevant

1. It must prove something (probative)

2. It must address the issue of a particular crime (material)

B. Reliable

Presenter is credible (has credentials and experience)

C. Hearsay is not admissible in criminal court but it is admissible in civil court.

1. Hearsay is information received from other people that one cannot adequately substantiate, rumor

7. 2. Two important legal decisions

A. 1. Fry standard

1. 1923, scientific evidence must be by an expert and have a general acceptance.

B. 2. Daubert ruling

1. 1993, judges dont have to go by the Frye standard as long as

a. Scientific theory is testable

b. It is subject to peer review

c. The rate of error is stated

d. It follows standards

e. There is consideration to acceptance

1E. The crime scene investigation team

1. Police Officers first to arrive

2. CSI investigators document scene and collect evidence

3. Medical examiners coroners, pathologists, doctors who study dead bodies

4. Detectives interview witnesses

5. Specialists entomologists (study bugs), forensic psychologists (profilers), weapon specialists, etc

1F. The seven Ss of CSI

1. Securing the scene

a. Done by the first responder

b. Safety is #1, preserving evidence is #2.

2. Separating the witnesses

a. Witnesses must not be allowed to talk to each other

b. Questions to ask the witnesses

i. What crime occurred?

ii. When did the crime occur?

iii. Who called in the crime?

iv. Who is the victim?

v. Can the witness identify the perpetrator?

vi. What did the witness see? Hear? Feel?

vii. Where were you when you observed the crime scene?

3. Scanning the scene

a. Primary crime scene where the crime was committed ex. In the convenience store

b. Secondary crime scene in some way related to the crime but not where the accrual crime took place ex. The suspects home.

4. Seeing the scene

a. CSI examiner

i. Photograph with and without a measuring stick

ii. Photos from many different angles

5. Sketching the scene

a. Rough sketches

b. All objects must be measured from at least 2 immovable landmarks

c. Includes doors, windows, North, scale to determine sizes

6. Searching for evidence

a. Must walk a pattern

i. Back and forth, spiral, grid

ii. Pattern must be systematic no area is left unsearched

iii. Use of flashlights and forceps (tweezers) is preferred.

7. Securing and collecting evidence

a. Proper packaging, sealing and labeling

b. Liquids and arson remains should be in airtight containers and sealed.

c. Biological evidence should be in breathable containers to prevent mold forming

d. Evidence should be sealed in another bag with tape and signed with the collectors name and date sealed.

e. Chain of custody its a record of who has taken, opened, studied the evidence,

i. The whereabouts of the evidence must be recorded at all times

ii. Everyone must keep a written record of when the get the evidence and the needed it for.

f. Evidence Log includes the case number, item number, description, name of suspects, victim, date and time of recovery, signature of person recovering evidence, signature of witnes