Randy Santos’ case is an abject lesson in how New York’s justice system now rushes to put dangerous individuals back on the streets. And, guess what, it’s about to get even worse.

Santos, accused of killing four other homeless men, had been arrested over a dozen times, including for assault and fare evasion. Yet two breaks left him free to roam.

In a turnstile-jumping case, a Brooklyn judge sent him to a supervised-release program — which Santos skipped out on. Then the Bronx Freedom Fund bailed him out on groping charges (though his other open warrants should’ve left him ineligible).

After Santos skipped another court date, an arrest warrant was issued, but never served.

Supervised release programs provide mental health counseling, drug treatment and other services that might well be appropriate in such cases — if they came with real teeth to ensure compliance.

But the system is too swamped to use even the powers it has to keep disturbed repeat offenders off the streets. And the Legislature has guaranteed that it’ll get worse come Jan. 1.

That’s when the new “no bail” law kicks in, removing judges’ discretion to remand defendants they deem a danger to the public. Programs like the one Santos skipped out on will be expected to handle and track a flood of new clients. Not that the Legislature added any funds for those programs, nor for all the other burdens the new law imposes.

Nearly all defendants, excepting only the most violent, will go free without having to post bail — and mostly without services that might keep them on the straight and narrow.

Consider those four dead homeless men in Chinatown just a sign of what’s ahead.