Rock musician David Crosby (search), founding member of the Byrds and Crosby, Stills, Nash and Young, pleaded guilty Friday to a gun charge, was fined $5,000 and sentenced to a conditional discharge.

Crosby, 62, pleaded guilty in Manhattan's state Supreme Court to attempted criminal possession of a weapon in the third degree as part of a plea deal. The charge carries a maximum penalty of four years in prison upon conviction.

Justice Michael R. Ambrecht said the case was discharged on the conditions that Crosby pay the fine and the court surcharges and avoid getting arrested again. Crosby's lawyer, Scott Herschman, said his client planned to pay the fine immediately.

The singer was arrested March 6 at the DoubleTree Suites Hotel in midtown Manhattan. Police said they found a Colt .45-caliber handgun (search), three clips of .45-caliber ammunition and two knives in his luggage.

Police also said the musician had a plastic bag containing an ounce of marijuana, a wooden container with a marijuana cigarette in it, a package of cigarette rolling papers and two other plastic containers with marijuana residue.

Crosby was arrested just hours after performing with his band, CPR, at a Wayne, N.J., college. He had checked out of the hotel but left behind a piece of luggage, police said. A hotel worker went through the luggage looking for identification, found the marijuana, gun and knives, and called police.

Crosby later called the hotel to say he'd be returning to pick up the luggage. Police greeted him when he showed up.