(George Frey/Reuters)

Writing in the Wall Street Journal, my old law professor Alan Dershowitz has raised a common objection to “red flag” laws — also known as “gun-violence restraining orders.” Put simply, Dershowitz argues that the government is not very good at predicting who will commit violent acts:

I have studied, taught and written for half a century about the difficulties of predicting violence. My first scholarly article, in 1970, was titled “The Law of Dangerousness: Some Fictions About Predictions,” and a subsequent book was titled “Preemption: A Knife That Cuts Both Ways” (2006). Research shows that any group of people identified as future violent criminals will contain many more who won’t be violent (false positives) than who will (true positives). More true positives mean more false ones. Such groupings also fail to identify many future violent criminals (false negatives).

He continues:

Red-flag laws risk setting a dangerous precedent. If the government can take your guns based on a prediction today, what will stop it from taking your liberty based on a prediction tomorrow?

But there’s a fallacy here. Red-flag laws aren’t “setting” precedent. They’re following precedent. Our legal system contains a host of laws that restrain individuals — and even deny them liberty — based evidence-based finding of future danger. Domestic violence orders of protection, restraining orders, and involuntary civil commitment (for people facing an acute mental health crisis) are commonly based on actions or statements that indicate an intent to inflict future harm. While many people who express suicidal or homicidal thoughts don’t kill themselves or others, countless Americans are grateful for processes that require a person to seek mental health treatments, bar them from access to homes or workplaces, or prevent them from maintaining personal contact with threatened individuals.

In fact, even the almost universally-supported prohibition against violent felons owning weapons is based in large part on prediction — the notion that violent criminals are disproportionately likely to re-offend. It’s dangerous to have guns in their hands.

Expressing a homicidal thought is obviously not the same thing as committing a homicidal act, which is why the law treats to the two things differently. There is no “pre-crime” conviction in American law. You won’t face life in prison for homicidal ideation, but you might face an injunction. You might be told to stay away from a spouse or an employer. You might even be committed until your symptoms improve. In some circumstances you should lose access to firearms for a limited period of time. This is a reasonable response to evidence of a threat.

Dershowitz ends his essay with this statement:

Red-flag laws would be worth trying as a remedy for gun violence if they remained limited to temporary gun confiscation pending a timely due-process review.

That’s exactly what good red-flag laws do. A good red-flag law is going to require that the petitioner come forward with admissible evidence, require the petitioner to carry a burden of proof, and provide advance notice of the hearing to provide the respondent with an opportunity to contest the claims against him. In emergency situations — where advance notice isn’t possible or prudent — the law should provide the owner with a prompt opportunity to contest the claims against him. And, at all times, the petitioners (those seeking the seizure order) must bear the burden of proof, and respondents should be granted the right of appeal.

There is no question that there are poorly-drafted red-flag laws, and merely slapping the “red flag” label on a law should not earn it presidential or legislative support. That’s why gun rights proponents should be directly involved in the drafting model legislation. Their presence helps protect the law against overbreadth and protects against abuse. I would urge everyone to read David Kopel’s Senate testimony regarding red-flag laws. He outlines fair procedures that provide law enforcement with an effective new tool while also protecting due process. He’s perhaps more cautious in some respects than I am, but a state law based on his procedural guidelines would be an important step forward.

No one thinks red-flag laws are a complete solution to the present contagion, but too many mass killers have exhibited obvious warning signs for our nation not to seriously consider how to respond to people who broadcast their dangerous designs.