WASHINGTON – In the liberal remake of “Casablanca,” the police captain comes upon the scene of the shooting and orders his men to “round up the usual weapons.”

It’s always the weapon and never the shooter. Twelve people are murdered in a rampage at the Washington Navy Yard, and before sundown Sen. Dianne Feinstein has called for yet another debate on gun violence. Major opprobrium is heaped on the AR-15, the semiautomatic used in the Newtown massacre.

Turns out no AR-15 was used at the Navy Yard. And the shotgun that was used was obtained legally in Virginia after the buyer, Aaron Alexis, had passed both a state and federal background check.

As was the case in the Tucson shooting – instantly politicized into a gun-control and (fabricated) tea-party-climate-of-violence issue – the origin of this crime lies not in any politically expedient externality but in the nature of the shooter.

On Aug. 7, that same Alexis had called police from a Newport, R.I., Marriott. He was hearing voices. Three people were following him, he told the cops. They were sending microwaves through walls, making his skin vibrate and preventing him from sleeping. He had already twice changed hotels to escape the men, the radiation, the voices.

Delusions, paranoid ideation, auditory (and somatic) hallucinations: the classic symptoms of schizophrenia.

So here is this panic-stricken soul, psychotic and in terrible distress. And what does modern policing do for him? The cops tell him to “stay away from the individuals that are following him.” Then they leave.

But the three “individuals” were imaginary, for God’s sake. This is how a civilized society deals with a man in such a state of terror?

Had this happened 35 years ago in Boston, Alexis would have been brought to me as the psychiatrist on duty at the ER of the Massachusetts General Hospital. Were he as agitated and distressed as in the police report, I probably would have administered an immediate dose of Haldol, the most powerful fast-acting antipsychotic of the time.

This would generally relieve the hallucinations and delusions, a blessing not only in itself, but also for the lucidity it brought on that would allow him to give us important diagnostic details – psychiatric history, family history, social history, medical history, etc. If I thought he could be sufficiently cared for by family or friends to receive regular oral medication, therapy and follow-up, I would have discharged him. Otherwise, I’d have admitted him. And if he refused, I’d have ordered a 14-day involuntary commitment.

Sounds cruel? On the contrary. For many people living on park benches, commitment means a warm bed, shelter and three hot meals a day. For Alexis, it would have meant the beginning of a treatment regimen designed to bring him back to himself before discharging him to a world heretofore madly radioactive.

That’s what a compassionate society does. It would no more abandon this man to fend for himself than it would a man suffering a stroke. And as a side effect, that compassion might even extend to potential victims of his psychosis – in the event, remote but real, that he might someday burst into some place of work and kill 12 innocent people.

Instead, what happened? The Newport police sent their report to the local naval station, where it promptly disappeared into the ether. Alexis subsequently twice visited VA hospital ERs, but without any florid symptoms of psychosis and complaining only of sleeplessness, the diagnosis was missed. (He was given a sleep medication.) He fell back through the cracks.

True, psychiatric care is underfunded and often scarce. But Alexis had full access to the VA system. The problem here was not fiscal but political and, yes, even moral.

I know the civil libertarian arguments. I know that involuntary commitment is outright paternalism. But paternalism is essential for children because they don’t have a fully developed rational will. Do you think Alexis was in command of his will that night in Newport?

We cannot, of course, be cavalier about commitment. We should have layers of review, albeit rapid. But it’s both cruel and reckless to turn loose people as lost and profoundly suffering as Alexis, even apart from any potential dangerousness.

More than half of those you see sleeping on grates have suffered mental illness. It’s a national scandal. It’s time we recalibrated the pendulum that today allows the mentally ill to die with their rights on – and, rarely but unforgivably, take a dozen innocents with them.

© 2013, The Washington Post Writers Group