This study estimated the number of unsolved cases (homicides, rapes, and property crimes) in the United States likely to have DNA evidence, and then it identified the problems facing State and local agencies in properly storing and accurately processing such evidence within a reasonable time period.
The study estimated that as of 2002 to 2003 there were 169,229 unsolved rape cases and 51,774 homicide cases that might contain biological evidence that had not been sent to a forensic laboratory for DNA testing. In addition, State and local laboratories reported 57,349 backlogged cases of rape and homicide waiting for DNA analysis. This brought the combined estimate of rape and murder cases that still required DNA review to as many as 278,352 throughout the Nation. The study estimated that as many as 264,371 property crimes with possible biological evidence had not been subjected to DNA analysis as of 2002 to 2003. One reason that so many unsolved cases had yet to be subjected to DNA analysis is police investigators' belief that forensic laboratories could not process such evidence quick enough to be helpful. Another reason is that local and regional forensic laboratories cannot afford the personnel, equipment, and facilities necessary to increase the volume of DNA analyses. More Federal support for DNA analysis is recommended. Responses were obtained from all 50 State laboratories and all 70 local laboratories from across the country. A random sample of approximately 3,400 law enforcement agencies was surveyed, with 1,692 completing the questionnaire. Estimates of cases not being subjected to DNA analysis were produced by a semiparametric method that involved a weighted decile approach. Results were cross-checked according to standard statistical diagnostic procedures. 6 tables, 5 notes, and 27 references