At 5 p.m. Eastern time, Lopez began shooting a semi-automatic .45 handgun he purchased in "the local area" but was not registered with the base, Milley said. Lopez was currently undergoing treatment for mental and behavioral health issues, including depression and anxiety. He was being evaluated for PTSD, but had not been diagnosed as of yet. Lopez served in Iraq for four months in 2011. He was married and "had family on base."

Within 15 minutes, a military police officer confronted Lopez, at which point he shot himself.

Milley said investigators had not come up with a motive for the shooting as of yet, though terrorism was not thought to be one of them.

"We know the community it strong, we know the community is resilient," Milley said.

9:55 p.m.: WFAA's Jason Whitely is reporting that the lockdown has been lifted.

8:41 p.m.: NBC News is now reporting that four are dead, including the shooter.

8:33 p.m.: NBC News reporting that three are dead -- not four -- including the gunman.

8:05 p.m.: Rep. Mike McCaul, Chairman of the House Committee on Homeland Security, told CNN's Erin Burnett that four people are dead and the shooter's name is Spc. Ivan Lopez. President Obama, currently in Chicago, told a group of reporters: "We're following it closely. The situation is fluid right now ... I want to just assure all of us we are going to get to the bottom of exactly what happened ... We're heartbroken something like this might have happened again."

AP Photo: President Obama delivers remarks on the Fort Hood shooting from Chicago http://t.co/iqLrcHeOLh pic.twitter.com/5XDvzJjaNF — Chicago Sun-Times (@Suntimes) April 3, 2014

7:54 p.m.: The Pentagon has confirmed that one person is dead and 14 are wounded.

7:30 p.m.: CBS News is now confirming the shooter is dead. AP is reporting that he killed himself, and that 14 are injured.

7:21 p.m.: CNN and NBC News are reporting that the shooter is dead. Both are citing unnamed officials.

7:00 p.m.: NBC News is reporting that a shooter is in custody, but authorities are looking into the possibility of more than one shooter. There are a multiple conflicting reports on the number of injuries, but almost all local news outlets have reported that one person was killed. CBS is reporting that witnesses say around twenty shots were fired both inside and outside of base buildings.

Fort Hood soldiers watching the news from Fort Irwin. pic.twitter.com/YYE9mv4oUn — Don Gomez (@dongomezjr) April 2, 2014

Earlier

WFAA has also confirmed that an active shooter is on the base. KVUE reports that the shooting took place in a medical brigade building. The official Fort Hood Twitter account also announced that all personnel are advised to shelter in place, but offered no other details.

The only statement given by Fort Hood is: "There has been a shooting at Fort Hood and injuries are reported. Emergency crews are on the scene. No further details are know at this time."

We are getting reports of an active shooting on Fort Hood. We will keep you posted as we get more information. — KWTX News 10 (@kwtx) April 2, 2014

BREAKING: Fort Hood confirms there has been an "incident on-post." UNCONFIRMED reports of an active shooter on the base w/ several injuries. — KVR News (@KVRNews) April 2, 2014

Last night, Fox News reported that the FBI had launched a manhunt for a former military recruit who had told friends he was planning a "jihad" attack, inspired by the 2009 shooting at Fort Hood. The FBI later downplayed that report, saying that an alert they issued about the suspect was real, but that he had been interviewed and was not considered a threat. (UPDATE: This appears to be a coincidence and unrelated to the shooting.)