ALHAMBRA, Calif. (Reuters) -- Legendary "Wall of Sound" record producer Phil Spector pleaded innocent on Thursday to murdering B-movie actress Lana Clarkson who was found lying in a pool of blood in February at his Alhambra, California, home.

The reclusive music impresario entered his plea during a brief hearing in Alhambra, 16 miles (26km) east of Los Angeles hours after prosecutors filed a single murder charge and allegations of implied malice and use of a handgun against him. A first-degree murder conviction carries a maximum penalty of life in prison with the possibility of parole.

A district attorney's spokeswoman said prosecutors believe Spector pulled the trigger but will allow a jury to decide whether the alleged crime rises to the level of first-degree murder. "We feel that the evidence that we have is sufficient," district attorney's spokeswoman Sandi Gibbons said.

The filing of charges closed the Los Angeles County Sheriff's nearly year-long probe into the Feb. 3 shooting of the tall blonde actress, who died of a gunshot wound to the head and neck in the marble foyer of Spector's faux castle.

Spector, 63, was arrested later the same day and quickly released on $1 million bail. He later said in a magazine interview that Clarkson, 40, had committed a bizarre suicide after "kissing" the gun.

The pair had met at the House of Blues on the Sunset Strip, where the statuesque star of such films as "Amazon Women in the Moon" and "The Barbarian Queen" worked as a hostess. On Thursday, Spector arrived at the afternoon hearing in a white stretch Hummer H2 accompanied by an entourage and his attorney, Robert Shapiro, formerly of O.J. Simpson's "Dream Team."