WIKIPEDIA: Federal Bureau of Investigation Laboratory
The Federal Bureau of Investigation Laboratory generally enjoys the reputation as the premier crime lab in the United States. However, during the 1990s, its reputation and integrity came under withering criticism, primarily due to the revelations of Special Agent Dr. Frederic Whitehurst, the most prominent whistleblower in the history of the Bureau. Whitehurst was a harsh critic of conduct at the Lab, coming to believe that a lack of funding and a pro-prosecution bias of the Lab technicians, who were FBI agents first and forensic scientists secondly due to the institutional culture of the Bureau, had caused the tainting of much evidence.
According to John F. Kelly & Phillip K. Wearne's 1998 book Tainting EvidenceTainting Evidence: Inside the Scandals at the FBI Crime Lab, the FBI Crime Lab had been hurt by a lack of funding and an institutional entropy rooted in Lab employees' belief that they were the best forensic experts in the country, if not the world. Lab employees failed to keep abreast of developments in forensic science. The two authors conclude that the worst problem was that the Lab employees were FBI agents rather than pure forensic scientists, and the investigative paradigm of the detective was an antithetical to the investigative paradigm of the scientist. Lab employees began to work backwards, from a conclusion preordained by the prosecutors they served, and sought to justify that conclusion rather than using more scientific research paradigms.
Whitehurst's whistleblowing and the adverse publicity trials in which FBI Lab employees were revealed as incompetent or disingenuous led to the implementation of reforms under then-FBI chief Louis Freeh.