NCJ Number
228202
Date Published
July 2009
Length
10 pages
Annotation
This paper first describes how (if at all) a "cold-hit" DNA match differs from a "weight-of-evidence" perspective in other cases in which DNA evidence is presented, followed by descriptions of the various approaches used to assess the strength of a DNA match in "cold-hit" cases.
Abstract
Crime investigations generally begin with one or more suspects being identified based on leads obtained from informants, witnesses, or personal identification clues (unrelated to DNA profiles) left at the crime scene. If the crime scene provides any biological sample that may be from the perpetrator, the DNA profile obtained from this sample is compared with that of a particular suspect. If there is a match, the DNA evidence is presented to show that the suspect was at the crime scene at some point in time. If there is no specific suspect in a case in which DNA evidence was obtained from the crime scene, or if the crime-scene DNA evidence does not match the DNA of the suspects being considered, then the DNA profile from the crime-scene evidence can be submitted to a DNA databank of offenders. A "cold-hit" occurs when such a search obtains a DNA match with the DNA of a person in the DNA database. Such a match can be followed up with an investigation of the person identified in the cold-hit. Such an investigation can include determining the sex of the person, any information on where he/she was at the time of the crime in question, and obtaining a corroborative DNA sample directly from the person identified in the cold-hit. The associated corroborative evidence obtained in cold-hit DNA cases can thus provide as strong a case as one in which a DNA match is obtained after a suspect has been identified from other evidence. 28 references