The shocking mistrial declared in the murder of Queens jogger Karina Vetrano has floored even veteran lawyers, who agreed Wednesday that the judge should have urged jurors to continue deliberating instead of calling it quits so quickly.

Queens Supreme Court Judge Michael Aloise excused the 12 jurors late Tuesday after they sent their first and only note declaring a deadlock following just 13 hours of deliberations.

In nearly all deadlocked cases, judges will read the jurors a so-called “Allen charge” — an instruction that encourages them to continue deliberating until they reach a unanimous verdict, lawyers pointed out.

“I have never seen [a mistrial] happen without an Allen charge. Never. The Allen charges normally work,” said defense attorney Sally Butler, who worked as a prosecutor in Queens for 15 years.

“Whenever you get that note, that’s the first thing the judge does. There was something definitely up.”

Experienced civil rights lawyer Ron Kuby agreed that the outcome of the trial, which started Nov. 5, was “unheard of” given the short length of deliberations.

“The first deadlock note, in my experience, never hangs the jury unless there is physical violence [among jurors] or other extraneous reasons,” Kuby said.

The panel had deliberated just 13 hours — one hour on Monday and 12 on Tuesday — after hearing a mountain of evidence against 22-year-old suspect Chanel Lewis, who is charged with sexually assaulting and strangling Vetrano in 2016.

“Given the amount of deliberation compared with the length of the trial, it was not a particularly long deliberation,” Kuby noted.

Reached at his home in Queens, Aloise, a judge since 2004, was mum when asked about the missing “Allen charge.”

“I’m sorry. I can’t comment on that,” he told a reporter with a smile after emerging from his car with some dry cleaning. “Have a happy Thanksgiving.”

Prosecutors have vowed to retry Lewis, who was remanded pending his next court date in January.

Butler said a hung jury gives the defense a leg up in the second trial “because you have a much better ability to then figure out where the weakness is.”

“Doing it again is a disadvantage for the prosecution,” she said. “Now the defense attorneys already know what the witnesses are going to say. If the witnesses screw up, they can say, ‘Wait a second, you said this before.'”

An “Allen charge” has been read before in other high-profile cases.

The Manhattan judge overseeing both trials in the Etan Patz case doled out the charge to jurors several times. The jury was hung in the first trial but the second ended with the conviction of Pedro Hernandez in the 1979 disappearance of the 6-year-old boy.

The legal instruction was also read in the trial against four people charged in connection with the murder of Gov. Andrew Cuomo aide Carey Gabay.

Additional reporting by Georgett Roberts, Emily Saul and Rebecca Rosenberg