A deranged brute charged with attacking two MTA workers and a transit cop last year was freed after cutting a deal to get psychiatric help — despite allegedly attacking four Rikers Island guards while he was locked up.

Christian Marrero, 21, not only blew off the psych program but is now charged with slashing three more innocent people in Queens during a rampage of random violence after he was let out of jail, according to officials and sources.

Only now is he behind bars without bail.

“It’s not at all shocking that another criminally insane person didn’t keep his word to attend psychiatric help,” one law enforcement source lamented to The Post.

“We’re never going to solve this problem until we place real consequences to any lack of adherence to mental health treatment. You either attend treatment or face the full effect of the law.”

Marrero was first arrested in June 2023 for allegedly attacking two MTA workers and a transit police officer two days apart in Manhattan.

According to criminal complaints, Marrero screamed out that he hated the MTA and slugged the first victim at 7th Avenue and West 148th Street around 2:30 pm on June 14, 2023. He then punched a second transit employee who came to assist his co-worker moments later.

Two days later, Marrero was outside 506 Lenox Avenue when he allegedly punched a transit police officer and spat in the cop’s face around 1:45 am, the complaints said.

He was locked up and spent nearly a year behind bars while the case was pending in court.

But on May 30, the Manhattan DA’s office, under embattled Alvin Bragg, said Marrero was allowed to cut a deal to enter an 8-month psychiatric treatment program — and would serve no more jail time if he completed it.

Records show that as recently as a week before he was offered the plea deal Marrero allegedly attacked a corrections officer on Rikers Island — the fourth time since February he was charged with assault on one of the jail’s officers while behind bars.

“It’s outrageous that a violent perp with a long track record of assaulting correction officers in our jails and New Yorkers in our communities would be given an opportunity to be released into a program, only to commit more violent crimes on our streets,” Benny Boscio, president of the city Correction Officers Benevolent Association, said in a statement on Sunday.

“Violent recidivists remain an ongoing threat to all New Yorkers and they must face serious consequences for their crimes committed in jail and on the streets, rather than just a slap on the wrist,” he said.

“This was a very poor decision and innocent New Yorkers are paying the price.”

It is unclear what agency ran the mental health program and whether it was in-patient or out-patient, but prosecutors said Marrero botched it and was hauled back into Manhattan court on July 1.

But by then he was facing three more charges in Queens, where he allegedly went on a crazed rampage on June 22 and attacked three different bystanders, slashing all of them in the face, records show.

According to a criminal complaint in that case, Marrero first attacked a straphanger aboard an E train at the Queens Plaza station around 8 a.m., causing cuts to his arm, face and ear — causing his ear lobe “to become partially detached.”

The man required 18 stitches to close the gash and “re-attach part of his ear lobe.”

But Marrero wasn’t done, prosecutors said.

At 8:20 a.m. he allegedly ran up to another man in front of 27-03 42nd Road in Queens and slashed him in the face before running off.

That victim required “surgical glue” to close the cut to his face, the complaint said.

At 8:23 a.m., Marrero allegedly attacked a third man in front of 42-57 27th Street and cut him “from his nose to his ear.” The victim required 30 stitches to close the gash.

Cops spotted Marrero at the Queens Plaza station about a half-hour after and arrested him.

The Manhattan District Attorney’s Office did not respond to an additional request for details on Marroro’s plea deal on Sunday nor about the treatment program he was supposed to complete.

Similar court-mandated programs have been the topic of controversy in the past, with critics questioning how effective they can be when attendance is up to the defendant.

Jordan Neely, the unruly vagrant who died in a fatal chokehold by ex-Marine Daniel Penny last year attended the court-ordered program for just two weeks before walking out.