The ex-Broadway hoofer charged with fatally shoving a retired teacher down Manhattan subway stairs posted an ominous online message last year before he went off the rails with a string of unhinged busts.

“Sorry, I had a MANIC EPISODE,” Rhamell Burke, 32, wrote on Facebook in July. “Do U still wanna f–k me?”

About six months later, the once-promising performer was then hit with the first of what would be four bizarre arrests before being charged with murder in the caught-on-video push of 76-year-old former educator Ross Falzone at the 18th Street station in Chelsea on Thursday.

Horrific footage shows the attacker walk up behind Falzone and give him a hard shove that sends the elderly victim flying through the air and onto the concrete steps below.

At the time, Burke was allegedly still wearing his wrist band from the psych ward at Bellevue Hospital, where he was taken by cops earlier in the day over an “emotionally disturbed person” call.

He fled the scene, then showed up in court Friday morning for a hearing in an unrelated assault rap. He was allowed to walk free after his hearing because no one had yet tied him to the subway attack.

NYPD detectives later spotted him at Penn Station and recognized him from surveillance images as Falzone’s alleged attacker. Burke was arrested and is now being held without bail on a second-degree murder rap.

It was an unnerving fall from fame.

Burke had posed with movie stars and was part of the ensemble of the hit Broadway show “King Kong” until 2019, before a friend said he lost it during the COVID pandemic.

In recent months, some of his online posts hinted at increasingly erratic behavior.

“Show your work: Torment vs. Torture,” he wrote on Facebook on April 30 — adding in what would be his final post, “From your soon to be Father of Philosophical Existentialism (think Toth or Hermes).”

Burke had been arrested by the NYPD four times since February, including for a meltdown at the Seventh Avenue and West 23rd Street station in Chelsea on Feb. 14, when cops responded to a report of a man with a shovel who allegedly smashed several doors and threw a trash can onto the tracks.

Three Port Authority cops were injured while making the arrest.

Mayor Zohran Mamdani told reporters Friday that he would called on the city’s hospital system to review its psychiatric evaluation process and discharge protocols to determine why Burke was released before the attack.

In a statement Monday, a City Hall rep told The Post that officials are “going through the review process right now” and added that the city hospital system and state health officials are also investigating.

Additional reporting by Matthew Fischetti