Jury to begin deliberations in trial of man charged with killing NYPD Det. Jonathan Diller, of Massapequa Park

A Queens jury is set to begin deliberations Wednesday in the murder trial of the man accused of killing NYPD Det. Jonathan Diller in 2024, after prosecution and defense attorneys gave nearly four hours of closing statements Tuesday.

Queens Supreme Court Judge Michael Aloise will charge the jury Wednesday morning, and the panel will begin deliberations on whether Guy Rivera, 36, is guilty of first-degree murder in Diller's death during a street incident on March 25, 2024, on Mott Avenue in the Far Rockaway section of Queens.

Rivera, who has a previous state gun conviction, is on trial not only for the murder of Diller but also the attempted first-degree murder of his partner, NYPD Sgt. Sasha Rosen, and various weapons possession charges. He is also charged with second-degree murder. He has pleaded not guilty to the charges.

In a ruling that could give the jury leeway to rule on a less serious homicide charge, Aloise is allowing the jury to consider a conviction of aggravated manslaughter in the first degree. Unlike the first-degree murder charge, which requires intent to kill, the manslaughter count requires intent to cause someone serious injury that then results in death.

The first-degree murder charge carries a potential prison sentence of life without parole, while the manslaughter offense is a class B felony, which could carry a sentence of 20 years to life, depending on other factors, such as a defendant's prior record.

Aloise’s courtroom was filled with Diller family members, including his widow, Stephanie, who at times covered her ears when police body camera videos were used by the prosecution and defense to make their points during summation, sometimes depicting the moment Diller was mortally wounded.

Dozens of police officers and officials with the Police Benevolent Association packed the courtroom.

During his nearly two-hour summation, defense attorney Jamal Johnson constantly pushed the idea that Rivera didn’t intend to kill Diller when he pulled his .38-caliber handgun, but that the weapon fired accidentally. The cause of the discharge, Johnson argued, was the intervention of Rosen, who he alleged grabbed Rivera’s gun hand.

“There's no intent to kill in this case,” Johnson told jurors. “All I ask is that you look at the evidence objectively.” 

With police body camera recordings and DNA evidence showing Rivera had the gun in his possession, Johnson conceded that his client was guilty of one of the weapons possession charges.

The 31-year-old Diller, of Massapequa Park, was part of a special community response team, an anti-crime unit, on a dinner break around 5:30 p.m. the day he was killed.

Trial evidence showed that Diller and other officers surrounded a Kia Soul in which Rivera was a passenger parked by 19-19 Mott Ave. Moments earlier, before Rivera entered the vehicle, Rosen testified he saw the outlines of a firearm in Rivera’s hoodie.

With Rosen suspicious that Rivera was armed, he, Diller and other officers went up to the car at which time Diller, who was standing by the passenger side door, asked Rivera to exit the car. All of the officers were dressed in distinctive khaki pants and had on raid jackets emblazoned with the letters “NYPD.”

Assistant District Attorney John Kosinski hit hard for 90 minutes on the argument to the jury that the trial evidence proved that Rivera indeed had intended to kill Diller. Kosinski, who heads to homicide bureau for the Queens District Attorney's Office, said Rivera had every chance to throw up his hands, surrender his illegal handgun and cooperate with police.

Kosinski also argued that video evidence and testimony showed Rosen never touched the gun in Rivera’s hand. He also said there was no gunshot residue on Rosen’s hands.

“Nobody was touching that gun other than that defendant,” Kosinski said.

Johnson had suggested in his closing argument that Diller’s police colleagues had a motive to lie or sculpt their testimony to assure a conviction. During the trial, Johnson also suggested police tried to abuse overtime and racially profiled at times.

But Kosinski struck back at such defense suggestions, saying, "If the evidence isn’t on your side, you have to come up with something else.”

In arguing that Rivera intended to kill Diller, Kosinski told the jury the defendant had a knife he could have used to confront the officers. But instead Rivera chose to use lethal force, he said.

“He wanted to get a jump on the cops," Kosinski said.