An ex-cop who once shared a jail cell with Jeffrey Epstein was convicted Thursday of killing four men in a cold-blooded murder spree in the Hudson Valley.

According to prosecutors, a Westchester County federal jury found former Briarcliff Manor police officer Nicholas Tartaglione responsible for the horrific 2015 murders of Martin Luna, two of his nephews, and a close family friend.

Tartaglione lured Luna to a meeting close to the Likquid Lounge in Chester, New York because the ex-cop thought Luna had stolen money from him, according to the prosecution. Tartaglione had switched from a career in law enforcement to illegal drug trafficking by 2015.

Luna brought along his two nephews, Miguel Luna and Urbano Santiago, as well as a friend named Hector Gutierrez, unaware that he was being led to his death.

Martin Luna was tortured and killed by being strangled with a zip tie by Tartaglione when the other four arrived.

After forcing the remaining three victims to kneel, the sadistic ex-cop and his two accomplices took them to a remote, wooded area where they shot them in the back of the head.

At the location in the woods, Tartaglione interred all four victims in one large grave.

“Tartaglione’s heinous acts represent a wider betrayal,” US Attorney Damian Williams said in a statement following the conviction. “He was a former police officer who once swore to protect the very community he devastated.”

Pedophile financier Jeffrey Epstein and Tartaglione briefly shared a cell in 2019 at the since-closed Metropolitan Correctional Center.

Epstein allegedly told his attorneys that Tartaglione “roughed him up” in the cell, but he was never charged with a crime and found not guilty, his attorney said at the time, according to The Washington Post.

In 2019, while Epstein was detained on suspicion of sex trafficking, he was discovered dead in his cell. The New York City Medical Examiner’s Office later determined that he committed suicide.

At sentencing, Tartaglione could receive a life sentence.