Police officers from around New York and the country gathered in Brooklyn Saturday to remember slain NYPD Detective Wenjian Liu.

The wake for Liu was held from 1-9 p.m. at the Ralph Aievoli & Son Funeral Home in the Dyker Heights section of Brooklyn.

Liu and his partner, Detective Rafael Ramos, were ambushed and shot to death in their patrol car on Dec. 20. The gunman killed himself in a nearby subway station.

The two officers were promoted to the rank of detective posthumously.

Gov. Andrew Cuomo attended Saturday's services, which came just two days after the death of his own father.

New York City Mayor Bill de Blasio and NYPD Commissioner Bill Bratton were saluted by officers as they entered the funeral home. It stood in contrast to last week, when hundreds of officers turned their backs to TV screens showing de Blasio's speech at Ramos' funeral outside the church.

Bratton had urged officers to be respectful at Liu's wake today, saying, "A hero's funeral is about grieving, not grievance."

Funeral services will be held in Brooklyn Sunday, and Liu will be buried at the same Cypress Hills Cemetery where his partner was also laid to rest.

Liu was a seven-year veteran of the force and leaves behind his wife of two months.