NEW YORK (PIX11) — Thousands of mourners gathered Thursday at a wake for fallen NYPD Officer Jason Rivera, one of two officers fatally wounded last Friday in Harlem.

Watch the procession for NYPD Officer Jason Rivera from the funeral home to St. Patrick’s Cathedral

The wake for the fallen hero at St. Patrick’s Cathedral in Midtown Manhattan began at 1 p.m. and was scheduled to end at 8 p.m. A funeral mass for Rivera will be held Friday, also at the famed church, with Cardinal Timothy Dolan presiding.

The 22-year-old had been a police officer for barely a year when he and his partner, Officer Wilbert Mora, were ambushed by a gunman at a Harlem apartment just one block away from their precinct.

Rivera’s wake comes a day after friends, family and colleagues gathered for a tearful vigil honoring both of the slain officers Wednesday night outside the NYPD’s 32nd Precinct.

The officers responded Friday night to a call for a family dispute involving 47-year-old Lashawn McNeil and his mother.

McNeil swung open the bedroom door and opened fire with a 45-caliber pistol outfitted with a modified 40-round clip, hitting both officers in the head. Rivera died that night, and Mora was pronounced dead Tuesday.

Mora, 27, was in his fourth year on the job. His wake and funeral Mass were planned for next week, also at the iconic Roman Catholic cathedral.

A third officer, Sumit Sulan, a rookie who was shadowing Mora and Rivera — shot McNeil as he tried to flee. The gunman, 47, died Monday, authorities said.

McNeil’s mother told the New York Post she was trying to convince her son to get help for mental health issues and that she wouldn’t have called 911 had she known he was going to use violence against the officers.