For John Lott, Wednesday's mass shooting at Fort Hood was a test of personal beliefs that struck uncomfortably close to home.
His son is serving at Fort Hood and was close enough to the activity to hear shots and screaming.
But he wasn't in a position to respond. Department of Defense policy forbids soldiers and sailors, in most circumstances, from carrying weapons at installations.
That frustrates Lott. For years, he has been promoting the idea — including in his book More Guns, Less Crime — that relaxing gun restrictions would make for a safer society.
"Even though my son just got back from a tour of duty in Afghanistan, where he had his gun with him all the time, he isn't able to have his gun with him on the base," Lott says. "We somehow don't trust people to carry a gun on base here."
Lott is not alone in this debate. With the third mass shooting at a military facility in five years, some members of Congress want to re-examine the policies that leave soldiers unarmed on base.
"I personally think if you're trained for combat, you ought to be able to carry a weapon," Michael McCaul, a Texas Republican who chairs the House Homeland Security Committee, said Wednesday on Fox News. "If they are trained in warfare [and] they can carry weapons in warfare, it seems to me there is some logic to allowing them to carry weapons on a military base, where they can defend themselves."
But it's not necessarily an idea that is going to catch on quickly in Congress. A bill along these lines was introduced last fall, after the shootings at the Washington Navy Yard that left a dozen people dead. But it has seen no action.
"I doubt there's going to be much support in Congress to allow military personnel to carry weapons on base," says Democratic Sen. Chris Murphy of Connecticut.
Weapons Are Prohibited
Last month, Defense Department officials released a report examining security in the wake of the Navy Yard shooting. The department concluded it had done a poor job securing the facility, screening personnel, and recognizing and addressing the mental health issues of the shooter.
The review included 14 recommendations for improving security. Letting soldiers carry weapons on base wasn't one of them.
The report recommended instead that signage be "posted conspicuously" at installations as reminders of the prohibition against carrying firearms in federal facilities.
"I don't think soldiers should have concealed weapons on base," Lt. Gen. Mark Milley, the commander of Fort Hood, said at a news conference on Wednesday.
It wasn't always the case that soldiers had to disarm while on post. Prior to the first Bush administration, base commanders determined what the rules were at their facilities. But regulations formalized in 1993 block personnel who are not on security duty from carrying firearms.
Further restrictions have followed. In the wake of the 2009 shootings at Fort Hood, which left 13 people dead, the installation requires soldiers to register their weapons with commanders.
"The carrying of privately owned firearms on Fort Hood is prohibited unless authorized by the installation's senior commander," according to guidance offered to soldiers stationed there. "The carrying of a concealed weapon on the installation is prohibited regardless of whether a state or county permit has been obtained."
But will a person intent on killing others care about violating such restrictions?
"The problem is you have these good, rule-abiding soldiers, but in this case, the killer knows everyone else is following the rules," Lott says.
Soldiers, Not Teachers
Fort Hood neighbors Killeen, Texas, a town where in 1991 a man named George Hennard drove into a Luby's Cafeteria and shot 50 people, killing 23 of them.
That massacre led to the state's concealed carry permit law.
"Do people have a right to protect themselves? They do outside the base," says Richard Feldman, president of the Independent Firearm Owners Association.
"Today, there would be some people who would fire back at George Hennard," he says. "If that makes sense outside of Fort Hood, why not inside, with trained personnel?"
After the school shooting at Newtown, Conn., in 2012, the National Rifle Association suggested arming and training teachers and other school personnel. That proposal was highly controversial, but the debate about letting soldiers carry firearms would have to take place on an entirely different footing, suggests Harry Wilson, a political scientist at Roanoke College and author of a book about gun control.
"Clearly, with the military, you can't make the argument that they aren't trained," he says. "It just doesn't begin to fly."
Following the shooting at the Navy Yard and now two shootings at Fort Hood, the military will have to examine the question of allowing soldiers to carry weapons, Wilson says.
"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," Texas Republican Rep. Steve Stockman, the lead sponsor of last fall's legislation to allow soldiers to carry guns, said in a statement on Thursday.
Prospects May Be Dim
Usually, it's the gun control advocates who are frustrated by their lack of success changing policies after a horrific incident. This time, it may be supporters of gun owners' rights who fail to achieve the changes they want.
Any move that loosens gun regulations seems unlikely while President Obama is in office. And policymakers will want to examine all the questions of risk that would be involved, from accidental discharges to the fear that fights between armed soldiers could escalate into serious violence.
If the Pentagon decides that it needs to heighten security by increasing the number of military police, that would be fine, says Murphy, the Democratic senator. Letting all or most personnel walk around with weapons, though, is another matter.
"This is ultimately the military's call, but there's no evidence that putting more guns into a community or into a workplace leads to less violence," Murphy says. "All the evidence tells us that the more guns you put into a location, the more likely there is to be more gun violence."