New method for processing rape evidence could eliminate crime-lab backlogs

With approximately 250,000 items of sexual assault evidence mired in three- to 12-month backlogs awaiting analysis in U.S. forensic laboratories, there is an alarming nationwide need for a time-efficient way to get this work done, according to a University of Virginia forensic researcher.

Jessica Voorhees Norris, a Ph.D. candidate in forensic chemistry at U.Va., has found a better way. She has developed a method for handling rape kit evidence that reduces part of the DNA analysis time from 24 hours to as little as 30 to 45 minutes and improves the sperm cell recovery rate by 100 percent. If her method was to be adopted by forensic labs – and the results accepted by courts – the backlog could potentially be reduced within months.

"There is an overwhelming demand for DNA analysis of sexual assault evidence, but laboratories have neither the funding nor the manpower to handle the caseload in a timely manner," Norris said. "Juries have come to expect DNA evidence in sexual assault cases, but forensic labs are not able to perform in a timely and efficient manner due to limitations in the currently used technologies."

Norris has spent much of her career working in laboratories and long ago realized that new methodologies would be needed to keep up with the growing accumulation of unanalyzed samples. She has devoted her doctoral research to developing more effective and time-efficient methods.

When a woman is sexually assaulted and comes forward to the police, a sample is taken from the vagina with a cotton swab, which is then sent to a forensic lab. In high-profile cases, the analysis is usually performed immediately, though overnight incubation is required to achieve a result.

In most routine cases, though, the sample is put into storage, sometimes for as long as a year, before it finally reaches its turn in the cycle to be analyzed or when the case approaches a court date. The sample may degrade during the waiting period, resulting in a compromised finding.