The show of disrespect came outside the funeral home where Officer Wenjian Liu was remembered as an incarnation of the American dream: a man who had immigrated at age 12 from China and devoted himself to helping others in his adopted country.
The gesture, among officers watching the mayor's speech on a screen, added to tensions between the mayor and rank-and-file police even as he sought to quiet them.
"Let us rededicate ourselves to those great New York traditions of mutual understanding and living in harmony. Let us move forward by strengthening the bonds that unite us, and let us work together to attain peace."
Buddhist monks led a Chinese ceremony for Liu, followed by a traditional police ceremony with eulogies led by a chaplain.
Police convened from around the US to mourn Liu, 32, who was killed Dec. 20. He had served as a policeman for seven years and was killed with his partner just two months after he got married.
"When one of us loses our lives, we have to come together," Grant said.
As Liu's family arrived for his funeral, Police Commissioner William Bratton tweeted: "We will never forget his sacrifice."
Liu and Ramos were fatally shot in a brazen daytime ambush on a Brooklyn street. The shooter, Ismaaiyl Brinsley, killed himself as police closed in after the shooting.
Investigators say Brinsley was an emotionally disturbed loner who had made references online to the killings this summer of unarmed black men at the hands of white police officers, vowing to put "wings on pigs."
