HUNTSVILLE, Texas — Attorneys for a Texas inmate want the U.S. Supreme Court to halt his scheduled execution for the shooting deaths of a 5-year-old girl and her grandmother during a birthday party 10 years ago outside a Fort Worth apartment.

Former Fort Worth street gang member Erick Davila is set for lethal injection Wednesday evening.

Lawyers for the 31-year-old Davila argue it's improper for the elected Tarrant County district attorney to be involved in the case because she was the judge at Davila's 2009 trial. They also contend evidence that Davila may have been high on drugs at the time of the shooting improperly was withheld from defense attorneys.

State lawyers are contesting the arguments.

Davila was convicted of killing Queshawn Stevenson and her 48-year-old grandmother, Annette Stevenson.