(Fort Hood, TX) Four people were killed in a shooting at Fort Hood Wednesday, including the shooter, CBS News confirmed.
Sixteen people were hurt, some critically, in the shooting.
All of those wounded or killed Wednesday were military personnel.
The shooter used a .45 caliber semi-automatic pistol in the attack and died of a self-inflicted gunshot wound, officials said Wednesday night.
The pistol was not registered on base as required.
Sources told CBS News the shooter had been identified as 34-year-old soldier Ivan Lopez.
Ft. Hood officials said the shooter served in Iraq in 2011 and had "behavioral health and mental health" issues.
They also said they do not yet know the motive, but that there was no indication the shooting was related to terrorism.
There are 40,000 people on the base.
After an attack at Fort hood in 2009, Maj. Nidal Hasan was sentenced to death for the murders of 13 people and for trying to kill 32 more.
Military personnel are not allowed to be armed on base.
The 2009 terror attack at Fort Hood was stopped by a civilian police officer who happened to be there and had her gun.
All personnel on post are asked to shelter in place.
— Fort Hood (@forthood) April 2, 2014
Fort Hood Army Wives is a Christian based business. We ask you to please take a moment & pray for the families & Troops on Fort Hood.
— FH Military Spouses (@FHMSPOUSES) April 2, 2014