Bedbugs in Forensic Cases: Their Importance

Bedbugs (or bed bugs) are small, elusive, parasitic insects of the family Cimicidae. In common use, the term usually refers to one species, Cimex lectularius, that feeds preferentially on human blood

Bedbugs have been around for thousands of years; have a distinctive smell, unusual sex habits and strong immune systems; and are useful in CSI cases as the bloodsuckers are living repositories of DNA evidence.

Bloodsucking insects are useful for forensic science because human DNA can be extracted from the meals that the bugs have consumed. Scientists at Texas A&M and Virginia Tech have successfully been able to isolate human DNA from bed bugs. It's been amplified and sequenced, and the biological material is of sufficient quality that it can be used to identify individuals. Proof of principle came in a paper published in 2006 in the Journal of Agric. Urban Entomol. Engorged bed bugs were collected from a human volunteer and from field sites in New York and Texas. The scientists found that viable DNA was retrieved from those bed bug specimens that had been alcohol preserved, air dried, and frozen.

The big advantage that these creatures have over other bloodsucking bugs for forensic science is that they don't stay with the host. So if police are after a fugitive and believe he/she stayed at a particular location, they could examine the bed bugs - if there is an infestation - because they would still be in the room long after the suspect had fled.