The Supreme Court has rebuffed Virginia's request to reinstate the death sentence of a convicted killer who claims he is too mentally disabled to be executed.

The justices on Monday did not comment in letting stand lower court rulings that threw out the sentence of death for Leon Winston, convicted in the shooting deaths of Anthony and Rhonda Robinson in 2002. Rhonda Robinson, who was pregnant, was shot to death in front of her 4- and 8-year-old daughters.

The lower court concluded that Winston's lawyers did not try hard enough to show Winston was mentally disabled, and thus, ineligible to be executed under a 2002 Supreme Court ruling.

The case is Pearson v. Winston, 12-492.