In the wake of yet more horrifying violence from a mentally ill homeless man, Mayor Bill de Blasio has … announced yet another review of how the city intervenes in these cases. Pathetic.

This will be de Blasio’s third such review going back to 2014. Nos. 1 and 2 dodged the obvious problems and solutions; don’t expect No. 3 to be different. Heck, it’s been four years since the mayor declared at a public forum on the rising homeless problem, “What we have to do better is deal with the mental health issue.”

Laurence Gendreau, identified as the man who brutally assaulted a 6-year-old boy in Queens on Thursday, had plenty of run-ins with the system. Same for Randy Santos, the alleged killer of four other homeless men last Saturday.

What the city desperately needs is a way to get such clear menaces off the street — and keep them off.

The mayor’s 30-day interagency review sounds on-target: It’s to look at all city mental health intervention programs and their use of Kendra’s Law, which allows judges to force mentally ill people into treatment.

But it’s a review by the mental health establishment that keeps failing here — because it doesn’t want to deal with the hard cases. Yes, the NYPD is to help lead the examination — but the city’s DAs, criminal courts and correction officials must be at the table, too.

Because they’re the ones who too often get stuck handling these cases after the mental health system punts. Plus, the criminal justice system is a key part of ordering Kendra’s Law interventions, including court-­ordered assisted outpatient treatment.

This is a question, above all else, of political leadership and will. Without that, the mental health establishment will simply divert any and all new energy and resources to everything but the tough cases — as it did with first lady Chirlane McCray’s ThriveNYC initiative.

No one wants the homeless population simply warehoused in jails, prisons or even psychiatric institutions — not even the segment that presents a clear public safety threat. But leaving these souls to roam as a threat to themselves and others is profoundly inhumane.

Get them off the streets — and get them help.