A Queens jury Wednesday found an ex-con guilty of manslaughter in the death of NYPD Officer Jonathan Diller in a trial marked by blistering emotional testimony from the slain cop’s widow and his grieving partners — plus a lone juror’s last-minute waffling that threatened to send the trial into disarray.

A Queens Supreme Court jury convicted Guy Rivera, 35, of aggravated manslaughter for Diller’s killing on Mott Ave. in Far Rockway on March 25, 2024. He was also found guilty of attempted murder and two counts of criminal possession of a weapon.

However, Rivera was found not guilty of murder.

According to a prosecution source, Rivera could face up to 90 years to life behind bars on the four counts.

Diller’s family cried and shook their heads in court at the verdict after Rivera ducked the murder charge. His widow, Stephanie, though, remained composed, nodding her head as Queens District Attorney Melinda Katz spoke to her afterward.

Earlier, the jury had been on the brink of convicting Rivera of manslaughter, but after the foreman read their verdict, a lone juror, Juror No. 5 answered “No” after he was polled.

Asked “Is this your verdict?” Juror No. 5 answered, “No.”

The judge considered sending the jury home for the evening, but then reconsidered, announcing, “Belay that order,” and the jury returned to deliberating, this time reaching a final, unanimous decision.

Diller’s daylight slaying shocked the city.  At his wake in Massapequa two years ago, a sea of police officers showed up to honor the three-year cop and family man who was hailed as a hero for his dedication to public safety. He left a wife and a young son.

Diller, 31, was working on his day off, as part of a five-officer team in the 101st Precinct, when another member of the unit, Sgt. Sasha Rosen, spotted an L-shaped object in the pocket of the suspect’s hooded sweatshirt.

Killer of NYPD Officer Jonathan Diller found guilty of manslaughter
Police secure a vehicle in front of 1919 Mott Ave. in Far Rockaway, Queens, after NYPD Officer Jonathan Diller was fatally shot while making a car stop on Monday, March 25, 2024. (Sam Costanza for New York Daily News)

Rosen and Diller followed Rivera until he got into the passenger seat of a parked Kia sedan, and within two minutes the officers and a third cop, Detective Dario Fernandez, surrounded the vehicle.

Diller got the attention of the other two members of his team, Detectives Veckash Khedna and Derval Whyte — and the tragic crack of a gunshot threw everything into chaos.

Prosecutors argued that Rivera reached for his gun and fired a single shot at Diller, hitting him in the stomach, then pointed his gun at Rosen’s chest, but the gun jammed. Khedna fired twice after the fatal shot, wounding Rivera.

Queens District Attorney Melinda Katz, left, and Stephanie Diller, widow of NYPD Det. Jonathan Diller, leave court after closing arguments in the trial of Diller's accused killer, Guy Rivera, at Queens Criminal Court in Queens, New York, on Tuesday, March 31, 2026. (Gardiner Anderson / New York Daily News)
Queens District Attorney Melinda Katz, left, and Stephanie Diller, widow of NYPD Det. Jonathan Diller, leave court after closing arguments in the trial of Diller’s accused killer, Guy Rivera, at Queens Criminal Court in Queens on Tuesday. (Gardiner Anderson / New York Daily News)

Rivera’s defense team tried to argue that the officers were involved in racial profiling when they stopped Rivera and that he didn’t deliberately shoot Diller. Rather, they argued, the gun went off inadvertently in a struggle after Rosen reached into the car and grabbed Rivera.

But jurors didn’t buy that argument, siding with prosecutors, who described Rivera as a cold-blooded killer, desperate to fight his way free of the cops surrounding the car, and who “made a calculated and deliberate action to point a loaded and operable firearm.”

Over the past three weeks, jurors saw video of the shooting from several angles, including the officers’ body-worn cameras, and heard testimony from Diller’s grief-stricken widow, the ER doctor who literally held the fallen cop’s heart in his hands as he tried to save his life, and all of the other officers present for the shooting.

DIller’s wife described their last morning together, their final “I love yous,” and their final phone call, when Diller said that he expected to be home early for dinner.

Det. Khedna, who shot and wounded Rivera after Diller was hit, told jurors he had a clearer view than the body-worn camera on his chest, and that he saw the gun in Rivera’s hand, stating, “He had full control of the gun.”