By Jeremy Schwartz, Austin American-Statesman

AUSTIN, Texas—Fort Hood’s strict personal firearms policies give commanders wide latitude in questioning gun purchases by soldiers they believe might be at risk of harming themselves or others.

But it’s unclear if Spc. Ivan Lopez’s superiors were aware of his March 1 purchase of a semiautomatic pistol at the Guns Galore shop in Killeen. And even if they were aware of it, a psychiatrist concluded just a month ago that Lopez wasn’t a threat to himself or anyone else, Army officials said Thursday.

Rules adopted last year would have given them, as well as the health professionals treating Lopez for anxiety and depression, the ability to question him about the purchase and even require him to turn in his private weapon if they deemed it necessary.

Fort Hood, along with the rest of the military, doesn’t allow most service members to regularly carry firearms while on post. It also requires soldiers to register and declare any personal firearm they plan to bring onto the installation. That requirement largely affects soldiers who live on post and are required to keep their weapons in a gun locker.

Lopez, who lived off-post, didn’t register the .45-caliber pistol he used in Wednesday’s attack, Fort Hood officials have said.

Secretary of the Army John McHugh said Thursday that officials “encourage” soldiers who live off-post to register their guns, but are prevented from requiring such off-post registration by federal law. However, the moment Lopez brought the unregistered firearm past the gate guard he was in violation of the regulation, McHugh said.

Officials say it would have been nearly impossible to detect the gun. After the 2009 mass shooting at Fort Hood, officials increased inspections of vehicles coming onto the massive Army post, where 70,000-80,000 employees and soldiers work. But Lt. Gen. Mark Milley, Fort Hood’s commander, said Thursday that it wouldn’t be feasible to “do a pat down search of every soldier and employee” coming onto the post.

Wednesday’s mass shooting at Fort Hood, which left four dead and 16 wounded, renewed efforts to repeal military rules that prevent most service members, with the exception of security and law enforcement officers, from carrying firearms on military installations.

U.S. Rep. Steve Stockman, R-Texas, blamed the shooting squarely on the policy, which derives from a pair of Department of Defense and Department of the Army directives enacted in the early 1990s. Critics believe that armed soldiers would have been able to stop the shooting earlier.

“This is the third mass shooting on a military base in five years, and it’s because our trained soldiers aren’t allowed to carry defensive weapons,” Stockman said in a statement Thursday. “It’s time to repeal this deadly anti-gun law before it creates another mass killing.”

Fort Hood adopted a slightly stricter version of the directive after the 2009 mass shooting on the post, giving commanders more leeway in requiring information from soldiers seeking to buy guns.

According to a 2013 update to the Fort Hood directive, the registration requirement is used to “protect service members and civilians from accidents or incidents that could result in death or serious injury.”

Deborah Cannon/Austin American-Statesman/MCT