A 70-year-old inmate who was sentenced to death in 1989 for murdering a woman after breaking into her home in Calaveras County hanged himself in his cell at San Quentin State Prison over the weekend, less than a week after a judge commuted his sentence to life without parole because of mental retardation.

On Saturday, a guard found George Smithey hanging from bedsheets he had twisted into a noose and tied around his cell bars, said Lt. Sam Robinson, a prison spokesman.

Smithey did not leave a note, Robinson said. The spokesman said he did not know whether Smithey had been told that a Calaveras County judge overturned his death sentence Aug. 23.

Smithey was convicted of murder, robbery and attempted rape in the death of Cheryl Nesler in April 1988. The state Supreme Court upheld his death sentence in 1999 but ordered the sentence reconsidered in 2008, based on the U.S. Supreme Court's 2002 ruling that executing the mentally retarded violates the constitutional ban on cruel and unusual punishment.

The judge at Smithey's 1989 trial had rejected a defense of mental impairment, said Deputy District Attorney Seth Matthews. But after the Legislature set new standards for retardation in response to the 2002 ruling, psychologists hired by the district attorney's office and Smithey's lawyers agreed that the inmate had been mentally retarded throughout his adult life.

Prosecutors did not oppose the Superior Court judge's decision Aug. 23 to resentence Smithey. Robinson said San Quentin would have transferred the inmate to another prison after it was formally notified of the decision.

Smithey's lawyers could not be reached for comment.

It was the second suicide at the prison in less than a week. Honorio Pantaleon, 33, of Santa Rosa, serving life without parole for fatally stabbing the mother of his children in 2008, was found hanging in his cell Aug. 23 with his throat cut. He died Friday.