CLAY COUNTY, Fla. -

A 26-year-old Orange Park man convicted of beating his girlfriend to death with a baseball bat in August 2006 was sentenced Monday to life in prison.

Joshua Maulsby was found guilty earlier this month of killing 19-year-old Alicia Castaneda after they got into an argument over laundry. Prosecutors played Maulsby's taped confession in court during the trial.

In it, Maulsby told investigators that he and his girlfriend had an argument at his parents' Orange Park home. He said he went to his car, got the bat and beat her to death, then dragged her body into a swimming pool.

Defense attorneys did not deny the killing for which Maulsby was convicted, but they disputed the state of mind of the defendant at the time of the killing.

"My opinion is he has a mental illness, factually understood that he was killing this individual but had no rational appreciation for the consequences of the wrongfulness of his actions," William Meadows, a forensic psychologist, testified in court.

After his arrest, Maulsby was found not competent for prosecution and was sent off to the state mental health facility in the Panhandle for treatment. He was returned to Clay County court in 2008 for a mental competency hearing and was later ruled competent to assist in his own defense.