Tragedy has struck twice at Fort Hood Army Base in Texas. Though details of the latest shooting rampage are still developing, here is a look at the 2014 and 2009 incidents.
•April 2, 2014: Spc. Ivan Antonio Lopez of Puerto Rico was identified as the gunman by Army officials. The father of three joined the National Guard in 1999 and later enlisted in the Army as an infantryman. Lopez was assigned to the 1st Armored Division at Fort Bliss. He switched his specialty to truck driver, the job he had during a four-month deployment to Iraq in 2011. Lopez saw no combat in Iraq. He transferred to the 154th Transportation Co. at Fort Hood in February.
•Nov. 5, 2009: Maj. Nidal Hasan, an Army psychiatrist, was born in Virginia and graduated from Virginia Tech. He was married and spent six years studying at Walter Reed Medical Center in Washington before moving to Fort Hood, according to military records. Hasan had been ranked outstanding in officer performance despite a poor record of medical performance and inappropriate discussion of his Muslim faith at work, according to government documents quoted by the Associated Press. At the time of the shootings, he was scheduled to deploy to Afghanistan.
•2014: Three servicemembers were killed and 16 wounded. All were military personnel.
•2009: 13 died and more than 30 were wounded in the deadliest domestic military attack in U.S. history. The victims were unarmed soldiers and one civilian.
•2014: Lopez was examined by a psychiatrist in March and found to show no violent or suicidal tendencies, said Army Secretary John McHugh, the U.S. Army's top civilian official. He said the soldier had been prescribed Ambien for a sleeping problem. Lopez was being evaluated for post-traumatic stress disorder but had not been diagnosed with the illness. He had "self-diagnosed" a traumatic brain injury, said Lt. Gen. Mark Milley, but "he was not wounded in action, to our records."
•2009: Hasan was "disgruntled because he had a poor performance evaluation, he doesn't believe in the mission, he's looking at getting transferred to Afghanistan or Iraq," McCaul said. "He's not happy about all that."
•2014: The shooter walked into a building in the 1st Medical Brigade around 4 p.m. and fired. He then got into a vehicle, fired more shots and went to another building and began shooting. Lopez killed himself in a parking lot at the transportation brigade's administration building.
•2009: The attack took place inside Building 42003, a soldier readiness building, where members of Hasan's unit and other soldiers gathered for final medical clearance before deployments to Iraq and Afghanistan. The building was torn down in February and will be replaced with a memorial park.
•2014: "There was no indication that he was targeting specific people," Milley said. "There may have been a verbal altercation with another soldier or soldiers," he said. "There is a strong possibility that that immediately preceded the shooting." The shooter appeared to have no connections to extremist groups, McHugh said.
•2009: Hasan said before his trial that he was a "soldier of Allah" who deserved martyrdom and that his attack was meant to protect Muslim insurgents abroad. From his opening statement Aug. 6, 2013, he admitted to being the gunman and pledged his allegiance to the mujahedin, or holy warriors.
•2014: A .45-caliber Smith & Wesson semiautomatic handgun. The Bureau of Alcohol, Tobacco, Firearms and Explosives traced the gun used in the attack to a gun shop, a federal law enforcement official who is not authorized to comment publicly said. The official confirmed that the gun had been purchased at Guns Galore, the same shop that sold a weapon to Hasan.
•2009: FN 5.7 semiautomatic handgun. Hasan reloaded high-capacity magazines several times and fired 146 rounds.
HOW IT ENDED
•2014: A female military police officer encountered the shooter in a parking lot, Milley said. Lopez, dressed in combat fatigues, reached to pull his weapon from under his jacket. The MP pulled out her gun and "engaged" from about 20 feet away, Milley said. Lopez put his gun to his head and fired a fatal bullet.
•2009: Hasan was shot and injured by post police. He was convicted on 13 counts of premeditated murder and 32 charges of attempted premeditated murder. He was sentenced to death by a military jury in August 2013. A report published in January 2010 found the initial response was "prompt and effective." First responders arrived on the scene less than three minutes after the initial 911 call. A minute and a half later, Hasan was incapacitated.