For a few hours after a gunman shot a member of Congress and four other people at baseball practice in the Northern Virginia suburbs on Wednesday, lawmakers were unified against the political vitriol that seemed to drive the attack.

But when questions inevitably shifted to how lawmakers would respond to the bloodshed of yet another mass shooting, it became clear that the brief display of agreement was more symbolism than substance.

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“There’s no empirical evidence to support the idea that more guns would make things better, and my study says it would make things worse,” Donohue told HuffPost in an interview.

There are a few simple reasons for this, said Donohue.

“Once everybody’s carrying guns, a lot of guns get lost and stolen, which means they’re in the hands of criminal right away,” Donohue explained. “Also, criminals start becoming a lot quicker to shoot when they think a lot of guns are in circulation, for the same reason police in the United States shoot a lot more people than police in England or France or Germany or Italy ― they’re afraid that they’re gonna meet somebody who’s got a gun.”

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“The NRA is always playing a game of checkers and the world is a game of chess, and if you play checkers in a world of chess, you almost always lose,” said Donohue.

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“It’s a hard enough thing for a well-trained officer or military person to respond to fire,” said Donohue. “It’s not a very easy thing for just your average Joe to do.”