INDIANA, Pa. -- Defense attorneys said a 19-year-old Indiana County man charged with fatally beating his girlfriend's toddler shouldn't be executed because tests show the man is mentally retarded.

State police said Joshua Turner, of Black Lick, told them he beat 19-month-old Leonard McIntire after the child bit Turner's finger and "wanted him to know what pain felt like."

Police said Turner first told them he was carrying the toddler on his shoulders when he fell and was hurt. But police said Turner eventually acknowledged beating, biting, shaking and punching the child on Oct. 27, 2008.

The toddler suffered a fractured skull, broken arm and had several bite marks on his body, police said. The medical examiner said Leonard died of blunt force trauma to the head.

Indiana County District Attorney Thomas Bianco said the victim's age is one reason why he's pursuing the death penalty if Turner is convicted of first-degree murder in the beating last October.

But Turner's attorneys said a psychologist last year determined Turner is retarded and the U.S. Supreme Court ruled in 2002 that retarded defendants cannot be executed.

A judge has not scheduled a hearing on the defense motion filed Tuesday.