4th Amendment
Part of the Bill of Rights that protects people from unreasonable searches and seizures.
5th Amendment
Rights that protect people from losing life, liberty, or property without due process of law. Also protects against self-incrimination and double jeopardy.
6th Amendment
Right to a speed and public trial by an impartial jury; to be informed of the accusation, to be confronted with the witnesses against him, to have opportunity to find witnesses in his favor, and to have the assistance of counsel for his defense.
Miranda Rights
You have the right to remain silent. Anything you say can and will be used against you in a court of law. You have the right to an attorney. If you cannot afford an attorney, one will be provided for you.
Probable Cause
Reasonable basis for believing that a crime may have been committed (for an arrest) or when evidence of the crime is present in the place to be searched (for a search). Can also justify a warrantless search or seizure.
Reasonable Suspicion
The lesser legal standard for performing searches; allows police to make inferences based on facts to make searches.
Reasonable Doubt
The highest standard of proof that must be met to convict a defendant in a criminal trial. There is no other logical explanation for how or by whom the crime could have been committed.
Admissible Evidence
Evidence that is permitted for presentation to a judge or jury during a trial; determined by the rules of evidence.
Direct Evidence
Evidence that establishes a fact; i.e. eyewitness testimony, confessions
Indirect/Circumstancial Evidence
Evidence which requires that a judge and/or jury make inferences about what transpired at the scene of a crime; strongly suggests a fact but does not prove it.
Individual Evidence
Evidence that can be linked to a unique, 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
Frye v. United States, 1923 ("Frye Standard")
the questioned scientific procedure or principles must be "generally accepted" by a majority of the scientific community
Daubert v. Merrell Dow Pharmaceuticals, 1993
Scientific technique used to analyze evidence must be tested, subjected to peer review, and subject to low rates of error.
Expert Witness
a highly specialized individual offers testimony on a scientific matter based on facts and the application of reliable principles and methods of analysis
Reference / Known Sample
Additional evidence that is collected for comparison against crime scene evidence. Ex: whole hair and blood samples from a crime victim; paint from the cars of four different suspects.
Questioned / Unknown Sample
Evidence that has been collected from a known location but is of unknown origin. Compared to a reference sample.
Chain of Custody
the witnessed, written record of all individuals
who had the evidence in their possession from the crime scene to the courtroom; and when, where, and for what purpose this transfer of evidence occurred
Double Jeopardy
When a defendant is tried twice for the same crime, usually in light of new evidence that was not available at the first trial.
Due Process of Law
Fair treatment through the normal judicial system, including a speedy trial and an unbiased judge and jury.
A.D.A.P.T.
Steps that should be taken when securing a crime scene.
Spiral Search Pattern
The investigator starts at the perimeter of the scene and works toward the center collecting evidence. Often used if there is only one investigator.
Line / Parallel Search Pattern
Multiple investigators walk across the crime scene at the same speed collecting evidence as they go.
Grid Search Pattern
Investigators perform overlapping searches across the scene (ex: north to south, then east to west)
Zone / Quadrant search
The CSI in charge divides the crime scene into sectors, and each team member takes one sector to search.
Triangulation
Method of measuring for a sketch in which two permanent objects are used as reference points for each piece of evidence.
Rectangular Coordinates
Method of measuring for a sketch where the distance of items from two perpendicular baselines is measured (walls are often used as baselines)
Polar Coordinates
Method of measuring for a sketch where distances from a central point and angles from a reference point are used for measurement.
gloves, mask, coveralls, slippers
Items worn by the crime scene investigator to prevent contamination of the scene
Golden Hour
The window of opportunity to collect time-sensitive information or evidence
Physical Evidence
any object that can establish that a crime has been committed or links a crime and the victim or suspect
Biological Evidence
samples of material from a human or other body�such as hair, tissue, bones, teeth, blood, semen, or other bodily fluids
Druggist Fold
method where a piece of paper is used to securely encloses small amounts of physical evidence such as a powder, hairs, or fibres
Integrated Automated Fingerprint Identification System (IAFIS)
national FBI database that houses the fingerprints and criminal histories of 70 million subjects; can be quickly searched for fingerprint matches
Combined DNA Index System (CODIS)
enables federal, state, and local forensic laboratories to exchange and compare DNA profiles electronically, linking violent crimes to each other and to known offenders
Integrated Ballistics Identification System (IBIS)
enable federal, state, and local law enforcement to digitally track and share information about firearms used in crimes
Plea Bargain
an agreement between a defendant and a prosecutor, in which the defendant agrees to plead guilty or no contest in exchange for reducing or dropping one or more charges or a less severe sentence.
Probative Value (of evidence)
usefulness of evidence in proving something important in a trial
Search Warrant
a legal document authorizing a police officer or other official to enter and premises and gather evidence
Defendant
an individual, company, or institution sued or accused in a court of law.
Prosecution
the institution and conducting of legal proceedings against someone in respect of a criminal charge.
Product (Multiplication) Rule
used to calculate the probability of multiple events all occurring or multiple pieces of indirect evidence matching one individual
Contamination of Evidence
may occur if evidence is not collected or stored properly; may invalidate evidence and make it inadmissible in court
Transient Evidence (type of physical evidence)
temporary; easily changed or lost; usually observed by the first officer at the scene. i.e. odors, temperature of evidence
Pattern Evidence (type of physical evidence)
produced by direct contact between a person and an object or between two objects. i.e. broken glass from a bullet passing through a window
Conditional Evidence (type of physical evidence)
produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event. i.e. lighting conditions, fire, rigor mortis
Transfer Evidence (type of physical evidence)
produced by contact between person(s) and object(s), or between person(s) and person(s). i.e. strangulation marks on a victim's throat
Associative Evidence
is something that may associate a victim or suspect with a scene or with each other; e.g.,
personal belongings.
Discovery
A phase in the litigation process during which the opposing parties may obtain information from each other and from third parties prior to trial.