Former President Donald Trump was on Long Island on Thursday to attend the wake of NYPD Officer Jonathan Diller, who was shot and killed during a traffic stop in New York City on Monday.

"The Diller family will inevitably never be the same. We have to stop, we have to stop them. We have to get back to law and order. We have to do a lot of things different," Trump said as he left the funeral home. "This is not working, its happening more. It's an honor to be here. Thank you all of you."

Trump arrived at the wake in Massapequa Park, N.Y., with Nassau County Executive Bruce Blakeman, a Republican who extended the invite to the former president. The 2024 GOP presumptive presidential nominee shook hands and briefly exchanged words with NYPD Police Commissioner Edward Caban, appointed by New York City's Democratic mayor, Eric Adams.

Diller, 31, and his partner were responding to a vehicle illegally parked at a bus stop in the Queens neighborhood of Far Rockaway on Monday evening when a suspect in the passenger seat pointed a gun at them and shot Diller, police said.

Diller's partner returned fire, hitting the gunman in the back, police said. The suspected gunman, Guy Rivera, remained hospitalized Thursday. Rivera was charged with first and second degree murder, first and second degree attempted murder, four counts of criminal possession of a weapon in the second degree and another criminal possession of a weapon charge in the third degree, Queens District Attorney Melinda Katz said in a release.

Police on Wednesday arrested the driver of the car on weapons charges. 

It was the first time an NYPD officer died on duty since January 2022. Diller had been with the NYPD for three years, police said. He leaves behind a wife and a 1-year-old son.

Adams, a former police officer, called Diller's shooting “devastating” and said Tuesday, “These are bad people doing bad things to good people. It’s the good guys against the bad guys.” On Thursday, New York Gov. Kathy Hochul said flags at state government buildings would be lowered to half mast on Saturday, the day of Diller's funeral.

President Joe Biden, Trump's Democratic rival, spoke with Adams and offered his support on Thursday, the White House said. Biden arrived in New York City later in the day for a major fundraiser with former Presidents Barack Obama and Bill Clinton.

"Our hearts go out, obviously, to the officer's family and the broader NYPD family, who have tragically lost one of their own. The president grieves for them and honors their sacrifice," White House press secretary Karine Jean-Pierre said aboard Air Force One en route to New York City on Thursday. "The president has stood with law enforcement his entire career and continues to stand with them as they put their lives on the line for their communities.  Under his leadership, we will continue to support police officers and ensure that they have resources they need to continue... to do the work."

Trump, a native New Yorker, has long highlighted crime in New York to needle Democratic officials who run the city and the state. He was also endorsed by two of New York City’s major police unions in 2020. And former NYPD Commissioner Bernard Kerik is an unindicted co-conspirator in the Georgia racketeering prosecution against Trump and his allies over alleged efforts to overturn the 2020 presidential election.

While he now largely resides in Florida, Trump still owns numerous buildings and businesses in and around New York City. He has also spent much time in the city in recent months fighting his various criminal and civil cases. Jury selection is expected to begin on April 15 for his criminal trial in Manhattan. He has been charged with allegedly falsifying business records in connection to hush money payments during the 2016 presidential campaign made to cover up an extramarital affair.

“We have violent criminals that are murdering people, killing people. We have drug dealers all over the place, and they go free and they can do whatever they want, but they go after Trump with this not even a crime,” Trump said after a hearing in that case on Monday.

The Associated Press contributed to this report.