PHILADELPHIA, Jan. 14 (UPI) -- A Philadelphia judge vacated the death sentence of a man convicted of killing a police officer, citing restrictions on executing the developmentally disabled.

Common Pleas Judge M. Teresa Sarmina ruled Friday the death penalty cannot be enforced against Edward Bracey, 50, convicted in the 1991 shooting death of police officer Danny Boyle, the Philadelphia inquirer reported Tuesday.

Bracey's sentence was reduced to life without parole. He was convicted of first-degree murder in 1992 and sentenced to death later that year.

Sarmina wrote Bracey, with an IQ of 74, possesses "major deficiencies in adaptive behavior," adding Bracey had established he was "mentally retarded" before his 18th birthday.

The U.S. Supreme Court ruled in 2002 the death penalty is unconstitutional for anyone defined by a state as mentally retarded, a ruling based on "evolving standards of decency" that have found "mentally retarded people are not sufficiently culpable," said Mark Bookman, director of the Atlantic Center for Capital representation.

Source: UPI, January 14, 2014