Two police officers, Wenjian Liu and Rafael Ramos, were killed in their patrol car in Brooklyn last Saturday by Ismaaiyl Abdullah Brinsley, a black man with a long history of arrest and mental instability. The shooting of the officers took place several weeks after a series of protests against police brutality erupted across the United States, in response to grand jury decisions not to indict the officers responsible for the deaths of Michael Brown in Missouri and Eric Garner in New York.
"It's time for everyone to put aside political debates, put aside protests, put aside all of the things that we will talk about in due time," the mayor said in a Monday speech to the Police Athletic League. "It is important, that regardless of people's viewpoints that everyone recognizes the time to step back and just focus on these families," he added.
Later the mayor attended a news conference, where New York Police Department Commissioner William Bratton, also spoke about the attack on Liu and Ramos.
"I had the opportunity today to talk with the leadership of all five of our police unions," Bratton said. "They are standing down in respect for fallen members until after the funerals, and then we can continue the dialogue that has begun about issues and differences that exist," he confirmed.
"We have to keep working for harmony between police and community. I believe we'll overcome this," Mayor de Blasio added.
Bratton asked for public assistance to find out the location of the killer during a few last hours of his life, from about 12 to 2.30 pm (GMT 17:00 – 19:30) on Saturday.
Officials said the killer acted alone. Security has been heightened across the city to prevent possible future attacks.
"We have received a number of what I would describe as copy-cat types of threats and we have been investigating those as you would expect with incredible care. As of this time, none of them have proven to be anything of significance," NYPD Commissioner William Bratton added.
According to the NYPD, Brinsley shot Wenjian Liu, 32, and Rafael Ramos, 40, in the head before running off towards the subway and killing himself. Earlier in the day he also shot his girlfriend, who is expected to recover.
US President Barack Obama condemned the murder and asked people "to reject violence and words that harm, and turn to words that heal," expressing sympathy for the family and friends of the officers killed.