An angry police source blasted the killing as a “complete collapse” of City Hall’s approach to mental health after a maniac repeat offender who had been released from a psych ward after just an hour allegedly shoved an elderly man to his death down Manhattan tube steps in an unprovoked attack on Thursday night.

Around 3:30 p.m. on Thursday, Rhamell Burke, a 32-year-old serial troublemaker who has been arrested four times since February, inexplicably left Bellevue Hospital an hour after being handcuffed and checked in as a “emotionally disturbed person,” according to police.

Around 4:40 p.m., the vi@lent monster was set free. Five hours later, while still wearing his hospital wristband, he k!lled 76-year-old stranger Ross Falzone, a teacher, at a Chelsea tube station.