Meet Daniel Floyd — the luckiest “killer” in New York.

The 23-year-old Brooklyn man was tried, convicted and — after the jury found he shot a rival dead at a dice game — sent to prison for 15 years to life. But the state’s highest court overturned the guilty verdict — all because Floyd’s mother couldn’t find a seat in the courtroom during jury selection.

A juror who voted to convict Floyd was shocked to learn of the stunning reversal.

“On a technicality like there was no room in the courtroom! That’s something new for me. I don’t think that’s right,” said the woman, who didn’t want her name used.

“Oh my gosh! This is very surprising, boy, because I didn’t know people could get off once they were convicted,” the 65-year-old public-school teacher said.

On Monday, Floyd was back in a Brooklyn courtroom for a pre-retrial hearing, as was the heartbroken mother of the man he had been convicted of killing.

“It’s very frustrating,” said Linda Dixon Hill, whose son, Leon Hill, was gunned down in the March 9, 2008, gambling dispute.

“He was found guilty by a jury [and then] the Court of Appeals overturned it,” she said sadly, adding that Leon’s daughter was 4 months old when he was killed. She is now 6.

Floyd’s conviction was tossed in an April 25, 2013, decision based on his trial lawyer’s complaint to Brooklyn Supreme Court Judge Michael Gary that Melissa Floyd was forced to wait outside a courtroom that was packed with potential jurors.

“Defense counsel observed, ‘Certainly, as a public spectator, she has an absolute right to be present,’ ” the decision states. “Defendants have a constitutional right to a ‘public trial,’ ” the decision goes on, adding that overcrowding does not justify courtroom closure.

“This violation . . . requires a new trial,” the judges ruled.

On his initial appeal, the Appellate Division had found Gary’s offer to get a seat for Floyd’s mom once some juror candidates had been weeded out was sufficient — and upheld the conviction. But the higher court disagreed.

Melissa Floyd declined to comment as she left court. But jurors who convicted her son were shocked to hear of the judicial U-turn.

“That’s a very bizarre reason,” said a male juror, 31, of Crown Heights. “What difference would it have made to the jury selection if she had been in the courtroom?”

Floyd and Hill argued over money on the dice table. Floyd stormed out and returned 20 minutes later, according to court papers — and allegedly fired a fatal shot into Hill’s neck.

Floyd’s current defense attorney, Mario Romano, said they were mulling whether to accept a plea deal or go back to trial.

Floyd, who remains incarcerated, will next appear in court Sept. 12.