Evidence

Background

Rules of evidence are created to assist in the search for truth and promote a fair process for both parties. Rules of evidence are the most important in common law criminal justice systems which retain the jury system, since it is thought that these rules safeguard against jury's giving inappropriate weight to certain types of evidence.

Certain rules of evidence also provide a deterrent effect against prosecutorial or police misconduct. Rules of evidence also improve efficiency of the court system, reducing the time required to try cases. Finally, some rules of evidence such as the attorney-client privilege and spousal testimonial privilege, are designed to affect out-of-court behavior.

• Materiality, Relevance, and Admissibility of Evidence
• Prejudice

Types of Evidence

• Direct evidence is evidence which, if true, proves a relevant fact conclusively. For example, eyewitness testimony is a type of direct evidence. Direct evidence is not necessarily more reliable than any other kind of evidence. See, Eyewitness Misidentification. Direct evidence establishes a material fact without the need for any inferences to be drawn by the trier of fact.
• Circumstantial evidence is evidence which indirectly, through inference, aids the trier of fact in inferring the existence of a fact in issue. For example, fingerprints or DNA found at the scene would be circumstantial evidence. Circumstantial evidence can be more reliable than direct evidence.

Testimonial Evidence

• Competency to Testify
• Confessions
• Similar Facts Evidence
• Expert Witnesses
• Hearsay

Privilege

• Attorney-Client Privilege
• Doctor-Patient Privilege
• Priest-Penitent Privilege
• Marital Confidences and Spousal Testimonial Privileges

Expert and Forensic Evidence

• Demonstrative Evidence
• Hair
• DNA
• Fingerprints
• Ballistics

Identification Evidence

• Eyewitness Misidentification

Evidence Codes

• United States Federal Rules of Evidence