An unstable former New York state trooper almost copped Wednesday to faking a shooting at a Long Island traffic stop — but derailed his confession by making another frank admission.

Thomas Mascia, 27, blurted out to a Nassau County judge that he was not in good mental health, moments before he was expected to plead guilty to charges connected to allegedly lying about being shot in the leg.

The candid admission briefly caused chaos in the courtroom, as it raised doubts in Judge Robert Bogle’s mind whether Mascia knew what he was about to do.

Mascia had been expected to admit he lied about being shot during a traffic stop, and plead guilty to three charges — tampering with evidence, official misconduct, and falsely reporting an incident.

The judge appeared visibly unsettled by the admission, flipping through paperwork and calling for a short recess as attorneys huddled in Bogle’s chambers to determine how to proceed.

Bogle ultimately opted to postpone Mascia’s plea agreement to May 21 after revealing that he signed court documents that morning as “Trooper Mascia” instead of Thomas, taking it as a sign that Mascia is indeed not doing well mentally.

He noted that even small details like that can raise red flags when someone’s competency is in question.

“The judge, just out of an abundance of caution, wants to make sure that his guilty plea is knowing and voluntary,” said his attorney Jeffrey Lichtman.

Lichtman explained his client was not aware of the consequences of his statements, but said he was honest to the judge about struggling with his mental health.

“You have to understand why we’re here today. We’re not here to celebrate his good work as an officer — we’re here because he’s suffering from significant mental illness,” Lichtman said.

Mascia has been receiving mental health treatment since the staged shooting, according to his attorney.

He and his parents, Dorothy and Thomas Sr., all wore green clothing to court in support of mental health awareness month, Licthman told reporters.  

All three declined to comment on their way out of court. 

“It’s a lot emotionally to deal with, and I think he’s sort of processing,” Licthman said of Mascia. 

“Doesn’t mean that he’s not capable of understanding what he’s doing here today.” 

The courtroom kerfuffle is the latest twist in a bizarre saga that began late Oct. 30 along the Southern State Parkway in West Hempstead.

Mascia claimed he had been shot in the leg during a traffic stop, prompting a massive manhunt for the gunman — but investigators quickly turned their suspicions on Mascia himself.

The now-former trooper may have staged the shooting for sympathy or even to win the attention of an “unrequited love,” officials said when he was charged in January with tampering with evidence, falsely reporting an incident and official misconduct.

Mascia was on track to plead guilty to the charges until he said he wasn’t in good mental health. After a brief chat with Lichtman, he tried to tell the judge he meant that he has been receiving mental health treatment since his incident — but to no avail.

“Look, if you shot yourself and lied about it and caused a multi-day manhunt for some nonexistent shooter, obviously he’s undergoing some severe mental health issues,” Lichtman later told reporters.