Mass shootings are horrendous things, something that I sincerely wish I would never have to write about again except maybe in a retrospective post about when they seemed to happen far too regularly. They’re awful things.

One thing that happens after such events is renewed vigor in the gun debate. Anti-gun crusaders use the corpses of the dead as a platform to push their agenda, then lash out at any pro-gun rhetoric as being somehow out of line in light of what happened.

The thing is, there has to be a reason why these events happen, one completely independent of firearm access. After all, millions of people have guns, yet only a tiny few commit these atrocities.

Over at The Volokh Conspiracy, there’s an interesting examination of some similarities in three major mass shootings.

The Stockton murderer could have been stopped before he started if the government had enforced existing criminal laws or had used existing laws to commit and provide mental health treatment for a plainly disturbed and imminently dangerous individual. The same has been true for many subsequent mass killers. In an article for the Howard Law Journal, Clayton Cramer and I detail other notorious homicides, including mass shootings, that could have been prevented if existing laws had been used to commit and treat people who were well-known to be severely and dangerously mentally ill.

A decade after Stockton, the law enforcement system failed again at Columbine High School. The year before Columbine, in the spring of 1998, the Jefferson County Sheriff’s Office had prepared an affidavit to ask for a search warrant for the home of one of the criminals. The affidavit was based on his published death threats on the Internet, and on the discovery—in a park a mile and half from his home—of bombs like the ones that he bragged about making. The fact of the never-executed search was unknown to the public until two years after Columbine, when Sixty Minutes II uncovered the affidavit by using Colorado’s Open Record Act. Why the Jefferson County Sheriff’s Office dropped the matter remains a mystery. The Office admitted in court that it had shredded many of its Columbine documents.

The pattern set by Stockton was repeated at Parkland High School, but even worse. There too, the criminal openly identified himself as an incipient mass murderer. The Stockton criminal’s various felonies at least had led to arrests and misdemeanor convictions, but the Parkland criminal’s open-and-shut felonies—such as explicit violent threats against the school—never even resulted in an arrest.

Part of the problem was apparently that the Broward Sheriff, and the school administration, were diligently implementing the Obama administration’s demand to shut down the “school to prison pipeline” by not arresting students. This was a reasonable policy for students who committed crimes such as truancy or possession of alcohol on school grounds. But it was not reasonable for the Parkland criminal’s assault and death threats. The criminal should have been put in a pipeline from school to prison. Instead, the Broward Sheriff and the school ended up running a school to graveyard pipeline.

In other words, the failures all appear to be related to law enforcement dropping the ball.

Look, I get that the police have a tough job, but in all three cases, we have deeply troubled people with a history of concerning behavior. Only in Columbine did the killers not purchase their weapons legally–they were too young and had to get a straw buyer–which would have likely been impossible had action been taken sooner.

These are the acts that are used to justify taking away our rights, but they shouldn’t be. These should be the acts that call for reform of our law enforcement system so that these oversights don’t continue; so that no one who exhibits these signs is given a free pass.

If taking away our Second Amendment rights was the only way–or even a way–to stop these killings, it would be one thing, but that’s not the case. Instead, we need to start with something that might make a difference without infringing on the constitutionally protected rights of people who have done nothing wrong.