Evidence (law)The law of evidence, also known as the rules of evidence, encompasses the rules and legal principles that govern the proof of facts in a legal proceeding. These rules determine what evidence must or must not be considered by the trier of fact in reaching its decision. The trier of fact is a judge in bench trials, or the jury in any cases involving a jury. The law of evidence is also concerned with the quantum (amount), quality, and type of proof needed to prevail in litigation.
Forensic scienceForensic science, also known as criminalistics, is the application of science to criminal and civil laws. During criminal investigation in particular, it is governed by the legal standards of admissible evidence and criminal procedure. It is a broad field utilizing numerous practices such as the analysis of DNA, fingerprints, bloodstain patterns, firearms, ballistics, and toxicology. Forensic scientists collect, preserve, and analyze scientific evidence during the course of an investigation.
EvidenceEvidence for a proposition is what supports the proposition. It is usually understood as an indication that the supported proposition is true. What role evidence plays and how it is conceived varies from field to field. In epistemology, evidence is what justifies beliefs or what makes it rational to hold a certain doxastic attitude. For example, a perceptual experience of a tree may act as evidence that justifies the belief that there is a tree. In this role, evidence is usually understood as a private mental state.
Insanity defenseThe insanity defense, also known as the mental disorder defense, is an affirmative defense by excuse in a criminal case, arguing that the defendant is not responsible for their actions due to a psychiatric disease at the time of the criminal act. This is contrasted with an excuse of provocation, in which the defendant is responsible, but the responsibility is lessened due to a temporary mental state. It is also contrasted with the justification of self defense or with the mitigation of imperfect self-defense.
WitnessIn law, a witness is someone who, either voluntarily or under compulsion, provides testimonial evidence, either oral or written, of what they know or claim to know. A witness might be compelled to provide testimony in court, before a grand jury, before an administrative tribunal, before a deposition officer, or in a variety of other legal proceedings. A subpoena is a legal document that commands a person to appear at a proceeding. It is used to compel the testimony of a witness in a trial.
