In the 2002 film “Minority Report,” Tom Cruise is, as usual, on the run. The film depicts a society that relies on “precogs,” psychics who can see the future to predict crimes so that a task force led by Cruise’s character can arrest and imprison the perpetrators of these crimes before they occur.

If Cruise plays the hero in this film, why is he on the run? Because even in this fictional world, it is impossible to predict with complete accuracy who will commit a crime. Cruise is shown murdering a man, and he is forced to run before he is placed in prison with all the other “criminals.”

The failure of this fictional system becomes particularly salient when considering many of the recent gun control proposals in the wake of the Sandy Hook shooting and others like it. A new focus on mental health has been called for. New laws passed in New York include increased authority for doctors and mental health professionals. The idea is that if they believe their patient may be a danger to others, they can notify the police, who will then either take the patient’s guns from them, or simply increase surveillance on them.

This policy is wrong. It places an inordinate amount of power in the hands of people who are not law enforcement officials. There is little supervision, and it is preposterous to believe there is such a high level of precision in certain mental health diagnoses. Many who are not a danger to others will have their rights taken away, and many who are a danger will continue to slip through the cracks.

There is no doubt that there are some people who are insane, and such people must be committed to treatment facilities for both their own and society’s best interests. But every time the guidelines for diagnosing these people are loosened, we slip further down the slope to the point where pre-crime becomes acceptable to us.

For as much discussion as there has been in recent weeks about the Second Amendment, the treatment of the Fourth Amendment, which protects against unreasonable search and seizure, is far more concerning. It should suffice to say that a process that leads to seizure of your possessions because a doctor declares you insane should be watched very carefully. It should ideally occur as little as possible, as once you are declared insane, your life is over. Everything you do to protest this fact can be understood as part of your illness. Even if you are released from the asylum to which you are committed, your chances of getting a job are irrevocably damaged by that gap in your resume.

It is important to ask why so much of this country’s recent discussion has focused on mental health. The answer is clear — it is a distraction used by the National Rifle Association and pro-gun pundits to prevent us from having the conversation about guns we need to have. We cannot possibly identify everyone who may commit a violent crime before they do so. But what we can do is limit criminal’s access to have access to the kinds of weapons that make these attacks so devastating. An attack on a school in China that occurred on the same day as Sandy Hook was lost in the wake of the American tragedy. Twenty-two kids were injured, but not a single one died. Why? Because the attacker had a knife, not an AR-15. Restricting access to guns universally is the answer, not denying certain people their fundamental rights.

A version of this article appeared in the Jan. 28 print edition. Ian Mark is a staff columnist. Email him at [email protected].