1. Forensic Science Legal Systems
Unit 3

2. 4th Amendment:
> The 4th Amendment: Rights of search and seizure…States that Unreasonable search and seizure is prohibited. >A Warrant IS necessary & MUST BE issued from the court. >If this right is violated it could cause a cases evidence to be ruled inadmissible in court & A GUILTY UNSUB TO BE FOUND NOT GUILTY.

3. How to decide if there is an invasion of the 4th Amendment:
> 2 Questions: a) Did the owner of the home or property that was investigated expect a “degree of privacy”? B) Was this expectation of privacy reasonable and legitimate? > Define Search warrant: - A judicial court order that authorizes the law enforcement agencies to conduct a search of a location/person and to seize any evidence of a criminal offense.

4. How to get a Search Warrant & When do you need it?
>Police must show the judge that there is: a) probable cause that a crime has occurred. B) And that Evidence linked to the crime may be found in the location or in the person. >A search warrant is not needed when: - Consent is given by person being searched - There is a life threatening emergency or destruction of evidence - After an immediate Arrest - Evidence is located in plain view - Reasonable suspicion of guns/drugs/evidence in location or on person

5. 5th Amendment
> Is Protection for an individual from being tried for the same crime twice. > In many cases a Grand jury- (16-24 citizens) meet to decided if there is enough evidence to take the case to court. >Double Jeopardy- it is very imperative that EVERY BIT OF EVIDENCE IS COLLECTED BEFORE THE CASE IS BROUGHT TO TRAIL because... If more evidence is found later and the person has already been “found innocent” They cannot be put on trial again for the same crime. >Due Process- Everyone must be treated the same.

6. 6th Amendment
> 6th- Rights to a speedy & public trail. >Depends on state statute, but generally there is 90 – 120 days for an imprisoned defendant, unless waived by the individual. > The following Have been known to slow the process: -The defendant is out on bail -Motions -Illness -Lack of attorney >the defendant has the right to an attorney: If they can’t afford one, the court must provide one A defense attorney must know every bit of the prosecutor’s evidence in the case to prepare The defense attorney’s job is to get the defendant freed—any and all evidence and evidence procedures can be questioned; this includes collection, handling, delivery, analysis, testimony, and documentation.

7. 7th Amendment
> Impartial Trial by Jury- Jury of the individual’s peers is the standard Some evidence and its analysis are very intricate, detailed, and difficult to understand outside of the scientific community; this can help or hurt the defendant. > United States Court– all courts used for trials should be controlled by the United States government. Meaning all verdicts handed down by these courts are final (unless appealed to a higher court.)

8. Evidence in Court
> Probative Value- Higher value of evidence that can prove something in court. > Probability- The mathematical description of occurrence of evidence. > Product Rule – calculate the overall frequency of occurrence of in a population.

9. Types of Evidence in Court
>Direct Evidence- The type of evidence presented by an eyewitness that establishes a fact. >Indirect Evidence- -Circumstantial evidence - Requires that a judge and/or jury make inferences about what happened at the scene of a crime. - Physical evidence that suggests, rather than making an observation…Does not prove a fact by itself…Not definitive proof. This type of evidence puts most innocent people in jail. > Circumstantial evidence is more objective, while direct evidence is subjective. In general, direct evidence is not considered to be as reliable as circumstantial evidence. Because The age of the eyewitness and the passing of time since the event can lead to faulty testimony.

10. Categories of Physical Evidence:
> Individual Evidence – evidence that can be linked to a unique and single specific source with a very high degree of probability. > Ex: -Matching ridge characteristics of fingerprints. -Matching striations of two different bullets from the same gun. >Class Evidence – evidence that can only be associated with a group and never a single source.

11. Evidence Admissibility in Court of Law
>Frye v. United States, 1923 – The Frye Standard: the questioned scientific procedure or principles must be “generally accepted” by a majority of the scientific community. A standard for admitting scientific evidence. > Daughbert v. Merrell Dow Pharmaceuticals, 1993: Verdict replaced the Frye Standard Areas of inquiry by the judge acting as the gatekeeper.

12. Federal Rules of Evidence – Expert Testimony
> Expert Testimony – hearsay (opinions of what others may have said in court) from a witness is normally not allowed in court, except in the case of an expert witness. > Expert Witness – a witness “qualified as an expert by knowledge, skill, experience, training, or education” and may present their opinion in a court of law. (Federal Rule #702) > guidelines that must be followed for forensic evidence and its results to be admissible in court: 1. A systemic search for all evidence must be conducted All evidence must be collected, including large items and trace evidence that must be vacuumed Comparison-type evidence should be collected when possible & Reference Samples – should be collected for comparison.

13. VOCAB:
> Odontology- Branch of forensics that uses teeth to identify remains. > Criminalistics- Branch of forensics that analyzes any physical evidence. >Ballistics- A branch of forensic science that investigates guns and tool marks. >Toxicology- A branch of forensics that looks for poisons in the body.

14. Other Important Facts:
> All forensic professionals should conduct themselves in an ethical way. > Substrate sample is a sample that is collected to ensure testing validity. > Evidence that can be related to a group of items with shared characteristics is called class evidence. > A written record of all people who have had possession of an item of evidence is called the chain of custody.