New York Mayor Bill de Blasio called Monday for a temporary halt to protests over police conduct as he faced a widening rift with a force preparing Christmas-time burials for two of its own and decrying the demonstrations as a factor in the officers' cold-blooded executions.
"I think it's important that, regardless of people's viewpoints, that everyone step back," Mr. de Blasio said in a speech Monday. "I think it's a time for everyone to put aside political debates, put aside protests, put aside all of the things that we will talk about in all due time."
Mr. de Blasio's relations with the city's police unions have tumbled to an extraordinary new low – one not experienced by a mayor in the nation's largest city in more than a generation – in the aftermath of Saturday's shooting, which the gunman claimed was retaliation for the deaths of black men at the hands of white police.
In a display of defiance, dozens of police officers turned their backs to Mr. de Blasio at the hospital where the officers died, and union leaders said the mayor had "blood on his hands" for enabling the protesters who have filled the streets of New York this month since a grand jury declined to indict an officer in the chokehold death of Eric Garner.
Mr. de Blasio, in his first extensive remarks since the killings, called for "everyone to put aside political debates, put aside protests, put aside all of the things that we will talk about in all due time."
Officers Wenjian Liu and Rafael Ramos were ambushed Saturday by a 28-year-old who vowed in an Instagram post that he would put "wings on pigs." The suspect, Ishmaaiyl Brinsley was black; the slain New York Police Department officers were Hispanic and Asian.
The killings came as police nationwide are being criticized following Mr. Garner's death and 18-year-old Michael Brown's fatal shooting in Ferguson, Mo. Protests erupted after grand juries declined to charge officers in either case.
Mr. de Blasio said it was time to focus on the officers' grieving families.
Investigators are trying to determine if Mr. Brinsley had taken part in any protests, or simply latched onto the cause for the final act in a violent rampage. He started off Saturday in Baltimore, shooting his ex-girlfriend in the stomach before coming to New York and killing the officers. He then ran into a nearby subway station and killed himself.
The police unions blame Mr. de Blasio for fostering an anti-police sentiment. Patrolmen's Benevolent Association President Patrick Lynch declaring that there was "blood on the hands," on the "steps of City Hall and the office of the mayor."
In an interview with NBC on Monday, Police Commissioner William Bratton said "what's quite apparent, obvious, is that the target of these two police officers was a direct spinoff of this issue of these demonstrations."
Even Mr. Bratton, who has steadfastly praised Mr. de Blasio, conceded that the mayor was on shaky footing with some in the NYPD. When asked if the mayor had lost the force's trust and confidence, Mr. Bratton said, "I think he's lost it with some officers."
Meanwhile, big-city police departments and union leaders around the country were warning the rank and file to wear bulletproof vests and avoid making inflammatory posts on social media.
A union-generated message at the 35,000-officer NYPD warned officers that they should respond to every radio call with two cars – "no matter what the opinion of the patrol supervisor" – and not make arrests "unless absolutely necessary."
The president of the detectives' union told members in a letter to work in threes when out on the street, wear bulletproof vests and be aware of their surroundings. At the same time, a memo from an NYPD chief asked officers to limit their comments "via all venues, including social media, to expressions of sorrow and condolence."
One directive warned officers in Newark, N.J., not to patrol alone and to avoid confrontation. In Philadelphia, police commissioner Charles Ramsey urged protest leaders to "call for calm and not let this escalate any further." Boston's police commissioner said officers there were on alert.
Officials in New York investigated at least a dozen threats against police since the shootings, and one man was arrested at a Manhattan precinct after he walked in and said: "If I punch you in the face, how much time will I get?" and refused to leave.