His partner, Officer Rafael Ramos, was also shot and killed. The two were sitting in their patrol car when it happened. The suspect, who later shot himself, had been making threats against police hours before the shooting.
Hundreds of people attended today's funeral, and officers from around the country traveled to New York City to pay their respects.
Among the sea of blue were two members of the Phoenix Police Honor Guard, including Officer Charles Holton.
Jet blue paid for the flights of all law enforcement members who wanted to attend.
Officer Holton spoke to Fox 10 via Facetime and said going to Brooklyn as part of the Phoenix Honor Guard was for him, also going home.
"I was very grateful to be a part of it and to experience it back in my hometown where I grew up," Holton said.
But this brief homecoming was a bittersweet one. It was a chance to see legions of officers honoring a fallen comrade, but also, a reminder of the tragedies that all too often come with the job.
"It's a beautiful thing, but at the same time it's disheartening because you are obviously experiencing the loss of one of your brothers in law enforcement, Holton said. "But it's an honor to be there and pay respect."
It's a duty the Phoenix Police Honor Guard takes pride in. Members represent Phoenix PD at funerals across the state and country.
"It's important for us to be there mainly for the families [of] the survivors; it brings such closure to them," said Commander Lisa Ruggiero with the Phoenix Police Department.
Today, thousands of officers from around the country mourned together and remembered a man who died serving his community. In officer Holton's 11 years with the department, this funeral is the largest he's ever been to.
"They never get easier, but they do contribute to how you perceive life and how you appreciate things and how you see the brotherhood of law enforcement," Holton said.