NCJ Number
93656
Date Published
1983
Length
33 pages
Annotation
This chapter discusses data gathered in a 2-year study of the uses and effects of scientifically analyzed evidence in police investigations from four jurisdictions: Kansas City, Mo.; Oakland, Calif.; Peoria, Ill.; and Chicago.
Abstract
Approximately l,600 case files were reviewed in which physical evidence had been collected and analyzed. Biological fluids and firearms were the primary evidence categories collected and analyzed in personal crimes, while fingerprints, trace evidence, and toolmarks were the leaders in property crime. The principal reason evidence was submitted to the laboratory, aside from drug evidence, was to associate persons, weapons, tools, and locations with one another. On the average, many more categories of evidence were collected in personal than in property crimes. Only a fraction of the evidence collected from the field was analyzed. The percentage of laboratory results leading to a statement of common origin was highest in personal crime, while property crimes returned the highest number of different origin results. Firearms, bloodstains, and toolmarks were the leading evidence categories in personal crime that successfully resolved questions of association among persons and location. In property crimes, trace and toolmark evidence were the main categories that resolved this question. Fingerprint evidence was most successful in identifying persons when collected in conjunction with other evidence in nonburglary/property crime cases. Tables are included.