Forensic DNA, PCR, and a Contested Sample

Edward Blake is a forensic consultant who ran Forensic Science Associates in California. He worked on high-profile cases, including the O.J. Simpson trial. He also performed DNA testing in the Roger Keith Coleman case and kept a small frozen sample from that case.

Modern PCR DNA testing lets labs examine very small or damaged samples so tests can give clear genetic matches. DNA testing has helped free hundreds of wrongfully convicted people in the United States. He kept the sample in his California laboratory for many years and resisted returning it to Virginia for retesting.