Former President Donald Trump on Thursday attended the wake of fallen NYPD officer Jonathan Diller, calling for a restoration of "law and order."

Diller, 31, was shot to death during a routine traffic stop in a Queens neighborhood earlier this week.

An NYPD spokesperson confirmed they were expecting the presumptive Republican presidential candidate at Diller's Long Island viewing, according to NBC News.

"What happened is such a sad, sad event, such a horrible thing," Trump, 77, told reporters outside the funeral home Thursday, where he was accompanied by a bevy of senior advisers, ABC News reported.

"We have to stop it. We have to stop it," Trump continued. "We have to get back to law and order. We have to do a lot of things differently, because this is not working."

Following Diller's death, Trump wrote on his social media platform, Truth Social: "To Officer Diller's family, and all of the other brave men and women of law enforcement who put your lives on the line every day, we love you, we appreciate you, and we will always stand with you!" NBC reported.

Diller, a husband and father to a 1-year-old, was shot beneath his bulletproof vest, allegedly by career criminal Guy Rivera, after he asked Rivera and a second suspect, Lindy Jones, to move their illegally parked vehicle from a bus stop, Headlines & Global News previously reported.

Diller was pronounced dead at the hospital shortly after.

Rivera, 34, who was shot in the back by Diller's partner during the incident, remains hospitalized, but is expected to recover.

He was charged with first- and second-degree murder, first- and second-degree attempted murder, and a slew of weapons-related charges, Queens District Attorney Melinda Katz announced Thursday.