Police from around US mourn with family of slain officer; thousands turn their backs on mayor

An honor guard walks along the procession route during the funeral of New York Police Department Officer Wenjian Liu, Sunday, Jan. 4, 2015, in the Brooklyn borough of New York. Liu and his partner, officer Rafael Ramos, were killed Dec. 20 as they sat in their patrol car on a Brooklyn street. The shooter, Ismaaiyl Brinsley, later killed himself. (AP Photo/John Minchillo) (The Associated Press)

CORRECTS VEHICLE IS NOT A HEARSE - The vehicle leading the funeral procession of New York Police Department Officer Wenjian Liu, seen in photo, passes along the funeral route as police officers salute, Sunday, Jan. 4, 2015, in the Brooklyn borough of New York. Liu and his partner, officer Rafael Ramos, were killed Dec. 20 as they sat in their patrol car on a Brooklyn street. The shooter, Ismaaiyl Brinsley, later killed himself. (AP Photo/John Minchillo) (The Associated Press)

Police officers salute along the procession route during the funeral of New York Police Department Officer Wenjian Liu, Sunday, Jan. 4, 2015, in the Brooklyn borough of New York. Liu and his partner, officer Rafael Ramos, were killed Dec. 20 as they sat in their patrol car on a Brooklyn street. The shooter, Ismaaiyl Brinsley, later killed himself. (AP Photo/John Minchillo) (The Associated Press)

Police officers from around the U.S. joined grieving family members as they mourned a 32-year-old immigrant who realized his dream of being an NYPD officer but was gunned down in his squad car.

New York City Mayor Bill de Blasio and Police Commissioner William Bratton eulogized Officer Wenjian Liu (WEHN'-jihn loo) on Sunday as an incarnation of the American dream.

But thousands of officers turned their backs as de Blasio spoke, repeating a display of scorn for a mayor who many officers say is anti-police.

Liu had served as a police officer for seven years and was married just two months when he was killed with his partner, Officer Rafael Ramos, on Dec. 20.

The officers' killer committed suicide shortly after the brazen daytime ambush on a Brooklyn street.