WASHINGTON (AP) — Officials say a shooting suspect at Fort Hood has been identified as Maj. Malik Nadal Hasan, who they say was an Army mental health professional.

A law enforcement official said Hasan, believed to be in his late 30s, was killed after opening fire at the base. The official spoke on condition of anonymity because he was not authorized to discuss the case publicly.

A defense official speaking on condition of anonymity says Hasan was a mental health professional — an Army psychologist or psychiatrist.

It was not known whether he was treating people at the base.

Officials says it was not clear what Hasan’s religion was, but investigators are trying to determine if Hasan was his birth name or if he may have changed his name and converted to the Islamic faith at some point.