Evidence
Part of the common law series
Types of evidence
Testimony · Documentary evidence
Physical evidence · Digital evidence
Exculpatory evidence · Scientific evidence
Demonstrative evidence
Relevance
Burden of proof
Laying a foundation
Subsequent remedial measure
Character evidence · Habit evidence
Similar fact evidence
Authentication
Chain of custody
Judicial notice · Best evidence rule
Self-authenticating document
Ancient document
Witnesses
Competence · Privilege
Direct examination · Cross-examination
Impeachment · Recorded recollection
Expert witness · Dead man statute
Hearsay (and its exceptions)
Excited utterance · Dying declaration
Party admission · Ancient document
Declaration against interest
Present sense impression · Res gestae
Learned treatise
Other areas of the common law
Contract law · Tort law · Property law
Wills and Trusts · Criminal law

This article is about the legal concept. For scientific evidence in pure science, see Scientific evidence. Image File history File links Scale_of_justice. ... The law of evidence governs the use of testimony (e. ... This article concerns the common-law legal system, as contrasted with the civil law legal system; for other meanings of the term, within the field of law, see common law (disambiguation). ... In law and in religion, testimony is a solemn attestation as to the truth of a matter. ... Documentary evidence is any evidence introduced at a trial in the form of documents. ... Physical evidence is any evidence introduced in a trial in the form of a physical object, intended to prove a fact in issue based on its demonstrable physical characteristics. ... Digital evidence or electronic evidence is any probative information stored or transmitted in digital form that a party to a court case may use at trial. ... Exculpatory evidence is the evidence favorable to the defendant in a criminal trial, which clears or tends to clear the defendant of guilt. ... Demonstrative evidence is evidence used to help the fact-finder gain context for the facts of the case. ... Relevance, in the common law of evidence, is the tendency of a given item of evidence to prove or disprove one of the legal elements of the case, or to have probative value to make one of the elements of the case likelier or not. ... In the common law, burden of proof is the obligation to prove allegations which are presented in a legal action. ... In law, to lay a foundation means to provide sufficient evidence of the authenticity and relevance for the admission of the testimony of a witness, documentary evidence, or other piece of evidence. ... A subsequent remedial measure is a term used in the law of evidence (law) in the United States to describe an improvement or repair made to a structure following an injury caused by the condition of that structure. ... Character evidence is a term used in the law of evidence in the United States to describe any testimony or document submitted for the purpose of proving that a person acted in a particular way on a particular occasion based on the character or disposition of that person. ... Habit evidence is a term used in the law of evidence in the United States to describe any evidence submitted for the purpose of proving that a person acted in a particular way on a particular occasion based on that persons tendancy to reflexively respond to a particular situation... In the law of evidence, similar fact evidence (or the similar fact principle) establishes the conditions under which factual evidence of past misconduct of accused can be admitted at trial for the purpose of infering that the accused committed the misconduct at issue. ... Authentication, in the law of evidence, is the process by which documentary evidence and other physical evidence is proven to be genuine, and not a forgery. ... The chain of custody is a concept in jurisprudence which applies to the handling of evidence and its integrity. ... Judicial Notice is a rule of evidence that allows a fact to be introduced into evidence if the truth of that fact is so notorious or well known that it is cannot be refuted. ... The best evidence rule is a rule of evidence in the United States that requires that when writings are introduced as evidence in a trial, the original writing must be produced unless the party can account satisfactorily for its absence. ... A self authenticating document, under the law of evidence in the United States is any document that can be admitted into evidence at a trial without any proof being submitted to support the claim that the document is what it appears to be. ... An ancient document, in the law of evidence, refers to both a means of authentication for a piece of documentary evidence, and an exception to the hearsay rule. ... This article is about witnesses in law courts. ... In law, competence is conerns the mental capacity of a individual to participate in legal proceedings. ... A privilege—etymologically private law or law relating to a specific individual—is an honour, or permissive activity granted by another person or a government. ... Direct examination (also called examination in chief) is the questioning of a witness by the party who called him or her, in a trial in a court of law. ... In law, cross-examination is the interrogation of a witness called by ones opponent. ... Witness impeachment, in the law of evidence, is the process of calling into question the credibility of an individual who is testifying in a trial. ... A recorded recollection, in the law of evidence, is a an exception to the hearsay rule which allows a witness to testify to the accuracy of a recording or documentation of their own out-of-court statement based on their recollection of the circumstances under which the statement was recorded... An expert witness is a witness, who by virtue of education, or profession, or experience, is believed to have special knowledge of his subject beyond that of the average person, sufficient that others may officially (and legally) rely upon his opinion. ... A dead man statute is a statute designed to prevent perjury in a civil case by prohibiting a witness who is an interested party from testifying about communications or transactions with a decedent, unless there is a waiver. ... Hearsay in its most general and oldest meaning is a term used in the law of evidence to describe an out of court statement offered to establish the facts asserted in that statement. ... An excited utterance, in the law of evidence, is a statement made by a person in response to a shocking event. ... In the law of evidence, a dying declaration is testimony that would normally be barred as hearsay but may nonetheless be admitted as evidence in certain kinds of cases because it constituted the last words of a dying person. ... A party admission, in the law of evidence, is any statement made by a declarant who is a party to a lawsuit, which is offered as evidence against that party. ... An ancient document, in the law of evidence, refers to both a means of authentication for a piece of documentary evidence, and an exception to the hearsay rule. ... Hearsay in its most general and oldest meaning is a term used in the law of evidence to describe an out of court statement offered to establish the facts asserted in that statement. ... A present sense impression, in the law of evidence, is a statement made by a person that conveys their sense of the state of certain things at the time the statement was made. ... This article is for the legal term Res Gestae. For the article on the record of the accomplishments of the first Roman emperor, Augustus, see the article for Res Gestae Divi Augusti. ... A learned treatise, in the law of evidence, is a text that is sufficiently authoritiative in its field to be admissible as evidence in a court in support of the contentions made therein. ... A contract is a promise or an agreement that is enforced or recognized by the law. ... This article or section does not cite its references or sources. ... Property law is the area of law that governs the various forms of ownership in real property (land as distinct from personal or movable possessions) and in personal property, within the common law legal system. ... In the common law, a will or testament is a document by which a person (the testator) regulates the rights of others over his property or family after death. ... The law of trusts and estates is generally considered the body of law which governs the management of personal affairs and the disposition of property of an individual in anticipation and the event of such persons incapacity or death, also known as the law of successions in civil law. ... Criminal law (also known as penal law) is the body of statutory and common law that deals with crime and the legal punishment of criminal offenses. ... The scientific method or process is fundamental to the scientific investigation and acquisition of new knowledge based upon physical evidence. ...

History

Establishing scientific evidence in the United States

Scientific evidence follows a predictable pattern. There are three "wise men" that need to be called to establish scientific evidence: the Educating, Reporting and Interpreting (ERI) expert witnesses.

Educating witness

Role

The educating witness teaches fact-finder (jury or, in a bench trial, judge) about the underlying scientific theory and instrument implementing theory. This witness is an expert witness, called to elicit opinions that a theory is valid and the instruments involved are reliable. The witness must be accredited as an expert witness, which may require academic qualifications or specific training.

• Judicial Notice: may moot the need for this witness.
• Qualifications: Relative experience based on complexity and subtlety of the subject-matter. This witness is on high plane of abstraction about the validity and reliability.
• Validity of Theory: Most jurisdictions require the theory used by an expert witness to meet certain qualifications before being used in court. The two most common are the Daubert and Frye tests.

Frye test

The Frye test calls for a theory to be generally accepted in scientific community.

This test results in uniform decisions regarding admissibility.

This test has been criticized as misunderstanding the scientific process and being based on the assumption that a jury is unable to evaluate scientific testimony.

Daubert test

The Daubert test arose out of the United States Supreme Court case Daubert v. Dow Chemical, 509 U.S. 579 (1993). It requires four things to be shown: The Supreme Court Building, Washington, D.C. The Supreme Court Building, Washington, D.C., (large image) The Supreme Court of the United States, located in Washington, D.C., is the highest court (see supreme court) in the United States; that is, it has ultimate judicial authority within the United States... // Case citation is the system used in common law countries such as the United States, England and Wales, Canada, New Zealand, Australia and India to uniquely identify the location of past court cases in special series of books called reporters or law reports. ...

• (1) Whether theory will help fact-finder (That is, whether the theory has or can be tested)
• (2) Whether theory has been peer reviewed (This is a component of good science and will improve likelihood the flaws will be found.)
• (3) Whether the theory has a significant rate of error
• (4) Whether the theory is "generally accepted" (not required but it helps to know scientific community approves.)

The Federal Rules of Evidence use the Daubert Test. See FRE 702. The Federal Rules of Evidence (FRE) are the rules that govern the admissibility of evidence in the United States federal court system. ...

Reporting witness

Reporting witness: Called after teaching witness leaves stand. Usually the laboratory tech. who personally conducted the test. Witness will describe both the test and the results. When describing test, will venture opinions that proper test procedures were used and that equipment was in good working order.

• Whether witness is qualified to conduct test. Could qualify as expert by virtue of "skill" gained through "experience & training" (FRE 702)—usually experiential, on-the-job training.
• Whether witness received the correct object to be tested. (Chain of Custody satisfying FRE 104(b)).
• Whether instrument(s) involved were in proper working order.
• Proof test procedures were used. This split the courts, but under CL, most Jx require foundational proof that the witness used proper test procedures on the occasion in question.
• Statement of Test Result: witness says what the results were. Excellent place to put physical evidence. Remember, validating scientific evidence raises a logical relevance issue, as does the authentication (e.g. with enlarged photo).

Interpreting witness

Interpreting (Evaluating) Witness: Sometimes not needed 1) when test result is self-explanatory or pass-fail, or 2) when there is a statutory presumption obviating the need (e.g. DWI statutes and a test showing > BAL). Otherwise, this witness needed to complete the foundation. Syllogistic in nature: 1) states the interpretive standard (Rule or Major Premise), applies the standard to the test result (minor premise) and derives a conclusion.

• Qualifications: a hybrid with both academic and experiential qualifications.
• Will base finding on the Reporting witness. [Experts may base opinion on 1) what personally observed, 2) facts that are the type of data customarily considered by practitioners of the specially and 3) hypothetically assumed facts.] Ideal if present when Reporter conducted test, but may be permitted in some jurisdictions.
• Some jurisdictions won't accept opinion unless it is a "reasonable scientific opinion." Otherwise, need to consider if the witness can couch the opinion in terms of statistical probably.

For example, in the casebook case of People v. Collins, 438 P.2d 33 (Cal. 1968), an elderly lady was knocked down and robbed by a blond who escaped in yellow car with bearded black man. Defendants met that rough description but could not be conclusively identified. Prosecutor used a mathematics professor to discuss the probability that this couple could be the guilty party. Lower court overruled Defendants' objection. Court held that 1) there was no foundational establishment of the underlying probabilities and 2) the fact that the Defendants' fit a probability model was irrelevant because it doesn't prove they did it. A casebook is a type of textbook used primarily by students in law schools. ...