PHILADELPHIA (AP) — Funeral services are Grant Prestonplanned Tuesday for a Philadelphia police officer killed in an airport parking garage shooting that also wounded another officer earlier this month.

A funeral Mass for Officer Richard Mendez is scheduled to begin at noon Tuesday at the Cathedral Basilica of Saints Peter and Paul in Philadelphia with family, friends, law enforcement personnel and dignitaries in attendance. Interment is to follow at Forrest Hills Cemetery in northeast Philadelphia.

Mendez and Officer Raul Ortiz had just started their shift around 11 p.m. on Oct. 12 when they heard breaking glass and saw several people breaking into a car in the parking lot at Philadelphia International Airport, police said. A confrontation ensued and the two officers and one of the suspects were shot.

Mendez, 50, who had been on the force for more than two decades, was shot four times and pronounced dead at a hospital, police said. Ortiz, also a 20-year veteran, was shot once in the arm and has since been released from the hospital.

Three men — Alexander Batista-Polanco, 21, of Scranton, Pennsylvania; Hendrick Peña-Fernandez, 21, of Pennsauken, New Jersey; and Yobranny Martinez Fernandez, 18, of Camden County, New Jersey — have been arrested and charged with murder and attempted murder. A fourth suspect, 18-year-old Jesus Herman Madera Duran, was shot during the confrontation and died at a hospital after being dropped off by his cohorts, police said.

Police believe one of the suspects alone fired the bullets that hit the two officers and Madera Duran, but they have left it up to prosecutors to detail exactly what happened. First Deputy Commissioner Frank Vanore said police believe the officers were trying to detain at least one suspect when “someone came behind (Mendez) and fired a weapon.”

In addition to the three prime suspects, police are pursuing others who either assisted the suspects or tried to obstruct the investigation, including those involved in burning a vehicle and renting hotel rooms and those who “knew where people were and didn’t tell us,” Vanore said last week. Investigators were also still searching for the slain officer’s gun, which they don’t believe was fired, he said.