CNN has obtained photos of Fort Hood shooting suspect, Ivan Lopez. Photos provided by Ruth Diaz with Puerto Rico National Guard
Deadly Shootings on U.S. Military Installations 1994-2014
March 2014: Naval Station Norfolk, VA - 2 Killed, including shooter
Sept. 2013: Washington Navy Yard - 13 Killed, including shooter
March 2013: Quantico, VA - 3 Killed, including shooter
June 2012: Fort Bragg, NC - 2 killed, including shooter
Nov. 2009: Fort Hood, TX - 13 killed
June 2009: Little Rock, AR, Recruiting Center - 1 killed
Oct. 1995: Fort Bragg, NC - 1 killed
March 1995: Naval Air Systems Command, Arlington, VA - Shooter killed
June 1994: Fairchild Air Force Base, Spokane, WA - 5 killed, including shooter
Military investigations are trying to learn everything they can about Iraq war veteran Ivan Lopez. The 34-year-old Army truck driver is accused of shooting and killing three people and wounding 16 others before killing himself on Fort Hood, Texas, Wednesday.
Following the second deadly shooting rampage at Fort Hood in five years, military investigators are today interviewing family, friends and fellow soldiers of Army Specialist Ivan Lopez.
They're trying to figure out what set the 34 year old off on a shooting spree that left four dead, including himself. Sixteen others were injured. It ended when Lopez took his own life after an officer confronted him in a parking lot.
Fort Hood's commander says doctors evaluated Lopez, looking for signs of post-traumatic stress disorder. He was taking medication for depression and anxiety and claimed to be suffering from a traumatic brain injury.
Officials say Lopez served in Iraq in 2011, but there's no evidence he was wounded there. The native of Puerto Rico arrived at Fort Hood in February.
Army officials say a preliminary check of Lopez's background revealed no significant criminal record and no links to terror groups.
"Possible extremist involvement is still being looked at very, very carefully," said U.S. Army Secretary John McHugh.
The shooting brought back memories of November 2009, when Major Nidal Hasan opened fire in a medical building at Fort Hood, killing 13 people and injuring more than 30.
The Pentagon instituted reforms to prevent future shootings. Now officials are trying to figure out how another tragedy has happened here.
Officials say Lopez used a recently-purchased 45-caliber semiautomatic pistol that was not registered for use at the base.