December 16, 2015 7:20 pm Suspect Will Use Insanity Defense in Murder of UMW Student Grace Mann News4 has learned that Steve Briel will use an insanity defense at his murder trial of Grace Mann. Local 0:36 1 dead, 2 hurt in shooting near DC's Fort Dupont Park 2:59 1 man dead, 1 man hurt in Centreville shooting: police 2:20 NTSB report reveals details about moments leading up to Key Bridge collapse 22:10 Voters head to the polls for Maryland primary: The News4 Rundown 2:27 A cyberattack temporarily shut down Metro's website last week