FILE - This file booking photo provided by the Stillwater Police Department shows Adacia Chambers, who is accused of running a red light and purposely driving around a barricade and over a police motorcycle before crashing into spectators at Oklahoma State University's homecoming parade. Legal experts say defense attorneys could have a difficult time proving that she is incompetent to stand trial. (Stillwater Police Department via AP, File)

NTSB: Driver sped up moments before Oklahoma parade crash

The woman accused of driving her car into spectators at Oklahoma State University’s homecoming parade and killing four people sped up as she…