NCJ Number
217230
Journal
Journal of Forensic Sciences Volume: 52 Issue: 1 Dated: January 2007 Pages: 128-136
Date Published
January 2007
Length
9 pages
Annotation
This study examined the factors that significantly influenced whether the DNA material recovered from a crime scene led to the identification, arrest, and charging of a suspect, using data on residential burglaries, commercial burglaries, and motor vehicle thefts investigated by the Northamptonshire Police (United Kingdom) in January-December 2004.
Abstract
The predictor found to have the most influence on whether or not DNA material recovered at a crime scene led to the identification, arrest, and charging of a suspect was the investigative skill of the officer who interviewed the suspect after a DNA match. This was particularly true when the DNA crime-scene source was "mobile" DNA (i.e., cigarette ends and chewing gum). It is easier for a suspect to provide an innocent explanation for the presence of his/her DNA on such items found at a crime scene. The skills of the interviewer determined whether or not such evidence led to a confession or incriminating statements by the suspect. Finding a DNA match from only blood at a crime scene was most likely to produce an arrest, regardless of the skill of the interviewer or the lack of any other DNA source evidence. The likelihood of a match and arrest increased, however, when multiple sources of DNA at the crime scene included cigarette ends, saliva, chewing gum, and cellular material. Thus, when there was no blood source for DNA at the crime scheme, the strength of the evidence increased when there were multiple DNA sources of the aforementioned types. The only DNA sources that produced matches and arrests when they were found outside the immediate vicinity of the crime were blood and cellular material. 3 tables, 9 figures, and 9 references