A lawyer for Phil Spector is seeking to reduce the convicted record producer's prison sentence by a year.

Attorney Doron Weinberg said in a court document filed Wednesday that Spector isn't disputing the mandated sentence of 15 years to life in prison for his second-degree murder conviction. But Weinberg wants a sentencing enhancement for use of a gun to be trimmed to three years instead of the four requested by prosecutors.

Weinberg's memorandum to the sentencing judge also says Spector isn't responsible in actress Lana Clarkson's death and that the prosecutors' case was based on "conjecture, not facts."

Spector was found guilty April 13 of shooting Clarkson at his home in 2003.

His sentencing is scheduled for Friday in Los Angeles.