Former President Donald Trump on Thursday attended the wake of slain New York Police Department Officer Jonathan Diller, whom officials say was shot and killed while conducting a traffic stop earlier this week.

"What happened is such a sad, sad event, such a horrible thing," Trump told reporters afterward.

In brief remarks, he reiterated his condolences for Diller's death and used the wake to focus on a frequent campaign season message about crime and public safety.

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

According to the NYPD's citywide crime statistics for the month of February, "incidents of shootings, murder, and other bellwether crimes in New York City were markedly reduced again in February compared to the same month last year."

The department went on to report that overall crime throughout the five boroughs "continued its downward trajectory, dipping another 1.1%."

On Monday, Officer Diller approached an illegally parked vehicle with another officer and asked the two suspects, Lindy Jones and Guy Rivera, to move their car, according to police. Officials say the two men refused to roll down their windows -- and instead of showing their hands as requested, Riviera allegedly shot Diller.

Diller was rushed to the hospital where he died.

Earlier Thursday, 34-year-old Rivera was charged with murder of a police officer, attempted murder and criminal possession of a weapon. His arraignment timing is unknown as he remains at Jamaica Hospital where he is being treated for a gunshot wound to the back after Diller's partner shot him after he allegedly fired his weapon. It's not clear if he has an attorney who can comment on his behalf.

Jones, 41, is charged with criminal possession of a weapon and possession of a defaced firearm. During a court appearance on Wednesday, prosecutors highlighted his violent history and missing court dates in arguing for holding him without bail.

Judge Maria Gonzalez agreed Jones poses a flight risk and remanded him. It's also not clear if he has an attorney.

Queens District Attorney Melinda Katz attended the arraignment in the courtroom packed with police officers, including Chief of Patrol John Chell.

Both suspects have a lengthy criminal history: Jones, who has had 14 prior arrests including attempted murder and robbery, was out on bail in connection to a separate crime, police records indicate. Rivera was previously arrested by the NYPD 21 times, according to police records.

Trump on Thursday seized on the fact that the suspects charged in connection with Diller's killing have criminal records.

"They don't learn because they don't respect. They don't," Trump said of Rivera and Jones. "They're not given the respect, the police are the greatest people we have. There's nothing and there's nobody like them and this should never happen."

On Tuesday, Trump, who also repeatedly commemorated slain police officers while he was in the White House, posted on his social media platform to mourn the death of Diller and rail against the alleged shooter, highlighting his prior arrests.

Trump also spoke by phone with the officer's family while they were at a funeral home on Tuesday.

After the wake on Thursday, Trump talked about meeting with Diller's wife and their child, saying their baby "doesn't know how his life has been changed."

Trump's appearance also comes on the same day as President Joe Biden's fundraiser in New York, which was planned well in advance of Thursday's wake. At the fundraiser, Biden will be joined by former Presidents Barack Obama and Bill Clinton. The event is expected to rake in a "historic" sum for a single event with more than $25 million, according to the Biden campaign.

Trump and the Republican Party's joint fundraiser in Palm Beach, Florida, next week is expected to raise at least $33 million, sources familiar with the event told ABC News.

Trump's campaign swiped at Biden for his "glitzy fundraiser" with "elitist" supporters on Thursday, though the White House has said that Biden spoke with New York City Mayor Eric Adams to share his condolences about Diller's killing and offer any support as needed.

The former president, who has been spending time away from the campaign trail, was in New York earlier this week for a court hearing in his criminal trial there involving hush money payments to Stormy Daniels. He denies any wrongdoing.

On the trail, Trump has frequently accused prosecutors of focusing on going after him rather than attempting to combat violent crime in the city, a claim which prosecutors reject. He has used Officer Diller's death to emphasize this point as he rails against crime in New York City.