NYPD detectives are "vigorously" pursuing a number of leads into the brutal slaying of an Ireland-born man in the Bronx last Sunday night.

John Kelly, 43, was shot once at close range in the back of the head while he was taking down Christmas lights.

An initial police statement pointed to the shooting as an act by "an unknown person for an unknown reason." The married father of three children was employed as the superintendent at 3505 Bruckner Boulevard, an apartment building where the shooting took place at around 8 p.m.

The Kelly family also lived in the building. Kelly, who was born in Sixmilebridge, County Clare, in Ireland and was a prominent figure in New York Gaelic Athletic Association circles, was rushed to Jacobi Medical Center. He was pronounced dead about an hour after the shooting.

The investigation into the shooting is centered at the 45th precinct where the head of the detective squad is Detective Sgt. Peter McCormack, who knew the deceased personally and told the Echo that detectives would vigorously pursue Kelly's killer.

In addition to his job as building superintendent, Kelly also worked Friday nights as a bartender, most recently at Jimmy Ryan's on Middletown Road in the Bronx. A work colleague of Kelly's at Jimmy Ryan's said that everyone who knew him at the bar was in a state of shock.

"We're devastated and shocked. Nobody can understand it," said the friend, who preferred not to be named. "He was a great person."

McCormack said that detectives were eager to hear from anyone in the Irish community or beyond who might have information helpful to investigators.

Note: Anyone with any information about the shooting is urged to call (718) 822-5414. Callers may remain anonymous.