Larry Pratt of GOA talks about the abuse of science at the FBI:
"Whitehurst also found that the FBI laboratory would often break a chain of evidence, thus making it impossible to prove that the "evidence" had not been planted. In some cases, it was planted. One example was that of the crime scene at Ruby Ridge, Idaho where U.S. Marshals and an FBI sharpshooter murdered a mother and her son and wounded two other family members. The physical record of the firefights did not support the depositions of the Marshals and FBI Agents, so one bullet was planted in a key spot to frame a family member and make it seem like he had been involved in the firefight when, in fact, he had not. Unfortunately for the government's case, the bullet was planted in two different directions in two different photographs."
"The bombing of the Murrah Federal Building in Oklahoma City resulted in the conviction of two perpetrators. Excluded from the stand were any witnesses who could not be dissuaded from reporting that they had seen middle eastern-looking men with Timothy McVeigh. "Working backwards" by one of the FBI's incompetent bomb experts, Dave Williams, excluded any investigation into why columns of the building collapsed which could not have been toppled by a fertilizer bomb parked on the street."
There's more. Check it out for yourself.