Difference between revisions of "Evidence"

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==Privilege==
 
==Privilege==
Certain witnesses may be able to claim a [[privilege]] against testifying in court. These privileges are created either by statute or common law and are designed to change out-of-court behavior of the parties.
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Certain witnesses may be able to claim a [[privilege | Objection:Privilege]] against testifying in court. These privileges are created either by statute or common law and are designed to change out-of-court behavior of the parties.
  
 
* [[Attorney-Client Privilege]]
 
* [[Attorney-Client Privilege]]

Revision as of 11:53, 3 November 2010

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.

Some evidence, even if material, relevant, and unprejudicial, may still be inadmissible if it was obtained in an illegal manner.

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.
  • Judicial notice is evidence that the court declares is proven through authority or common knowledge.
  • Real evidence is some actual physical item involved in the case. For example, the murder weapon is real evidence.
  • Demonstrative evidence is a depiction, prepared for trial, that represents an item involved in the case. Following are some examples of demonstrative evidence: photo of the murder weapon, surveillance camera footage, computer simulations, diagrams, maps, x-rays, videotape, illustrations or any other item specifically created for trial.

A criminal defense attorney may object to real or demonstrative evidence on the following grounds:

  1. No identifying witness
  2. Gaps in chain of custody
  3. Opportunity for tampering or contamination occured
  4. Item is not a true or accurate depiction of what it purports to be.

Testimonial Evidence

Privilege

Certain witnesses may be able to claim a Objection:Privilege against testifying in court. These privileges are created either by statute or common law and are designed to change out-of-court behavior of the parties.

Expert and Forensic Evidence

Expert opinion evidence may be admissible at trial based on relevance, necessity, policy, and qualification. The function of an expert is to provide the judge or the jury with a ready-made inference which the judge and jury, due to the technical nature of facts, are unable to formulate. If the judge or jury can form their own conclusions without aid of an expert, then the expert opinion is unnecessary.

Expert opinion is usually held to a higher level of scrutiny. An expert must be qualified and credible and criminal lawyer or prosecutor may have to give advance notice to the court that they will be bringing an expert to trial. The expert should be available for cross-examination on the issue/science of this testimony, as well as on their credentials.

In the United States, the judge acts as a gatekeeper for expert opinion. Judges generally use the Daubert Standard [1] to determine whether evidence is admissible, though some courts still use the Frye Test.[2]

Identification Evidence

Evidence Codes

Notes

  1. Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579(1993)
  2. Frye v. United States, 293 F. 1013 (D.C. Cir. 1923)