Watch the Moment When NYPD Officers Turn Their Backs on the Mayor

As New York City Mayor Bill de Blasio was heading to make his first public statement after the killing of two police officers, a group of uniformed cops turned their backs towards him.

The moment was caught on cell phone video.

The move, meant as a clear sign of disrespect, came Saturday night when de Blasio was walking into Woodhull Hospital with NYPD Commissioner Bill Bratton to give their first press conference following the shooting Saturday afternoon.

The unions representing the police and the sergeants both issued statements criticizing the mayor after the killings, which Bratton described as "mindless assassinations."

The move against the mayor wasn't the only way that the police used actions to convey a message.

Hundreds of officers were seen paying tribute to their two slain comrades with a silent salute as the vehicle carrying their bodies drove away from the hospital.