Forensic Casework Samples
In a 2001 survey of public DNA laboratories, the Bureau of Justice Statistics (BJS) found that between 1997 and 2000, DNA laboratories experienced a 73% increase in casework and a 135% increase in their casework backlogs. Many casework samples go unanalyzed for lack of a suspect to which to compare the biological evidence from the crime scene. These are often referred to as "no-suspect" cases.
There is a significant backlog of casework samples that has been caused by a massive demand for DNA analyses without a corresponding growth in forensic laboratory capacity.
Through data collected from a large, representative sampling of local law enforcement agencies in the United States, an NIJ-funded study from 2003—National Forensic DNA Study Report (pdf) —arrived at the following estimates:
- The number of rape and homicide cases with possible biological evidence which local law enforcement agencies have not submitted to a laboratory for analysis is over 221,000.
- Homicide cases - 52,000 (approximate)
- Rape cases - 169,000 (approximate)
- The number of property crime cases with possible biological evidence which local law enforcement agencies have not submitted to a laboratory for analysis is over 264,000.
- The number of unanalyzed DNA cases reported by State and local crime laboratories is more than 57,000.
- State laboratories - 34,700 cases (approximate)
- Local laboratories - 22,600 cases (approximate)
- Total crime cases with possible biological evidence either still in the possession of local law enforcement, or backlogged at forensic laboratories is over one half million (542,700).
