In a 2005 Census of Publicly Funded Crime Laboratories, the Bureau of Justice Statistics (BJS) found the typical laboratory performing DNA testing began the year with a backlog of 86 DNA cases and finished the year with 152 backlogged cases (a 77% increase in the backlog). Using data collected in a similar BJS census of publicly funded crime laboratories conducted in 2002, the typical DNA laboratory received 337 new DNA cases in 2005, compared with 246 new cases in 2002 (a 37% increase in the number of DNA cases submitted to the laboratory).
The significant backlog of casework samples is caused by a 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: