National Transportation Safety Board
Assistance to criminal investigations The NTSB has primary jurisdiction over civil transportation investigations, but not criminal investigations.  If the Attorney General declares the case to be linked to a criminal act, the NTSB must relinquish control of the investigation to the Federal Bureau of Investigation.  The NTSB may still provide technical support to the FBI in such investigations.  In two high-profile examples, the NTSB sent aviation accident investigators with knowledge of aircraft structures and flight recorders to assist the FBI's criminal investigation into the murder-suicide of Pacific Southwest Airlines Flight 1771 in 1987, and the September 11, 2001 attacks fourteen years later.