HACKENSACK, N.J. (AP) _ Former hit man Salvatore ``Sammy the Bull'' Gravano, who helped bring down mobster John Gotti, has been charged with murder for allegedly arranging the 1980 killing of a New York City police officer, a prosecutor said Monday.

Gravano was charged on Wednesday in the death of Peter Calabro, a day before another admitted hit man, Richard Kuklinski, pleaded guilty to pulling the trigger, Bergen County Prosecutor John L. Molinelli said.

Gravano hired Kuklinski a month before the shooting and provided the shotgun Kuklinski used to kill Calabro, 36, of Upper Saddle River, Molinelli said.

Molinelli would not give a motive, and said he did not know why Gravano, who was a hit man for the Gambino crime family, used Kuklinski to kill the officer.

The charge was not revealed until Monday to avoid compromising the investigation, said homicide chief James Santulli, an assistant Bergen County prosecutor.

Gravano, who is imprisoned on drug charges, could be brought to New Jersey within several weeks to face the single murder count, unless he opposes extradition, Molinelli said.

Since New Jersey did not have the death penalty in 1980, neither Kuklinski nor Gravano could be executed.

Kuklinski was charged after he confessed to the slaying in an interview broadcast May 20, 2001, on the HBO series ``America Undercover.''

Molinelli said Gravano, who later became a government informer, hired Kuklinski to kill Calabro and provided Kuklinski with ``the specific weaponry and equipment needed to carry out the homicide.''

Gravano also was in the area at the time Calabro was killed, the statement said. Calabro's body was found in a station wagon with two shotgun wounds on March 14, 1980.

Gravano was the government's star witness in the case against Gotti in 1992. He admitted plotting 19 murders as a mob hit man but served only five years in prison on racketeering charges under a deal with prosecutors. He settled in Arizona after leaving prison.

Gravano is now in prison in Colorado, where he is serving state and federal sentences for masterminding an Ecstasy drug ring while he lived in Arizona.

Gotti was found guilty on 14 counts, including murder, racketeering and tax evasion and received a life sentence. He died last year at a prison hospital in Missouri.

Kuklinski, known as The Iceman because he kept some victims' bodies in a freezer, is serving a 60-year prison term on four murder convictions. He accepted a plea bargain Thursday that calls for him to serve a concurrent 30-year state prison term. He will be sentenced April 11 and will not be eligible for parole until 2046.