Crime Lab Problems

In recent years, the integrity of crime laboratories has been called into question, with some heavily publicized cases highlighting (1) unqualified practitioners, (2) sometimes lax standards that have generated questionable or fraudulent evidence, and (3) the absence of quality control measures to detect questionable evidence. In one notorious case, the Texas Department of Public Safety confirmed serious inadequacies in the procedures used by the Houston Police Department Crime Laboratory, including routine failure to run essential scientific controls, to take adequate measures to prevent contamination of samples, to adequately document work performed and results obtained, and to follow correct procedures for computing statistical frequencies. There have been a number of other dismaying reports about crime labs--most recently, the San Francisco drug lab--that suffer from problems like those uncovered in Houston.

Judge Harry T. Edwards in Forensic Testimony (2013) by C. Michael Bowers