PHILADELPHIA — Hundreds of mourners lined up in the pouring rain outside a cathedral Friday to pay their respects to a Philadelphia police officer killed in the line of duty.

A horse-drawn caisson traveled about a mile through city streets before dawn to bring Sgt. Stephen Liczbinski's casket from police headquarters to the Cathedral Basilica of Saints Peter and Paul, where a funeral Mass was held.

Liczbinski, 39, a 12-year veteran of the police force, was fatally shot on Saturday as he responded a robbery at a bank inside a supermarket.

One of three suspects in the holdup was killed shortly afterward by police. A second man was taken into custody on Sunday and a third suspect was captured late Wednesday night.

Police Commissioner Charles Ramsey, speaking to pews packed with officers and loved ones, said Liczbinski's death "represents the kind of heroism that takes place throughout the country every single day by the men and women in uniform."

"Steve is not a hero in my mind because of how he died," Ramsey said. "He's a hero because many years ago he made the decision, he answered a call, he knew that he wanted to help others. ... He chose to become a police officer."

Outside the packed cathedral, hundreds of people gathered to watch the funeral Mass on video screens.