Falsified evidence, forged evidence or tainted evidence or misleading by suppressing evidence unfavourable for the police/prosecution, is used to either convict an innocent person, or to guarantee conviction of a guilty person. In Britain this is known as 'Noble Cause Corruption'. Some evidence is forged because the person doing the forensic work finds it easier to fabricate evidence than to perform the actual work involved. The planting of a gun at a crime scene would be used by the police to justify a shooting, and avoid possible prosecution for manslaughter. The fact that the police/prosecution, (one of the parties with a vested interest in a trial), effectively controls the supply of most or all of the evidence, is a fundamental problem of the adversarial trial system.
New York State Police Troop C scandal
In the New York State Police Troop C scandal
of 1993, Craig D. Harvey a New York State Police trooper was charged with fabricating evidence. Harvey admitted he and another trooper lifted fingerprints from items the suspect, John Spencer, touched while in Troop C headquarters during booking. He attached the fingerprints to evidence cards and later claimed that he had pulled the fingerprints from the scene of the murder. The forged evidence was used during trial and John Spencer was sentenced to 50 years to life in prison.
FBI Crime Lab scandal
In the 1990s, the fingerprint
, and explosive units of the FBI Crime Lab
had written reports confirming local police department theories without actually performing the work. The scandal led New York State police authorities to establish stricter guidelines in the handling of forensic evidence.
Such laws and regulatory procedures stipulating the conditions under which evidence can be handled and manipulated fall under a body of due process statues called chain of evidence rules. It is crucial for law enforcement agencies to scrupulously collect, handle and transfer evidence in order to avoid its falsification. In most jurisdictions, chain of evidence rules require that the transfer of criminal evidence be handled by as few persons as possible. To prevent error or improper tampering, chain of evidence rules also stipulate that those authorized to experiment with collected evidence document the nature, time, date and duration of their handling.
- National Law Journal; October 9, 1995; "Faked Evidence Becomes Real Problem-From Fingerprints to Photos to Computer Data, Lawyers are Learning to be Vigilant"
- New York Times; November 22, 1992, Sunday; "Ripples of a Pathologist's Misconduct In Graves and Courts of West Texas. The prairie graveyards of West Texas are giving mute testimony to the misdeeds of a circuit-riding pathologist who left a trail of faked autopsies, botched blood samples and missing organs from the Panhandle to the Rio Grande. According to defense lawyers' estimates, as many as 20 capital murder cases ..."
- John F. Kelly and Phillip K. Wearne; Tainting Evidence: Inside The Scandals At The FBI Crime Lab