HOUSTON (AP) - A divided federal appeals court panel has upheld the death sentence of a Jefferson County man convicted of killing a Port Arthur firefighter who arrived at his sister's home during a robbery where his two teenage nieces also were being raped.

Lawyers for 42-year-old Elroy Chester contended he was mentally impaired, making him ineligible for execution under U.S. Supreme Court guidelines for the 1998 shooting death of Willie Ryman III. .

Two judges on a three-judge panel of the 5th U.S. Circuit Court of Appeals agreed Friday with prosecutors who said Chester was not mentally impaired. A third judge said the majority ruling was contrary to federal law established by the Supreme Court.

Chester, who was linked to at least five murders and three rapes, pleaded guilty to Ryman's slaying.