AUSTIN, Texas/PHILADELPHIA (Reuters) - A court ordered an 11th-hour stay to Pennsylvania's first execution in 13 years on Thursday.
Hubert Michael Jr. was one of two convicts scheduled to be executed in the United States on Thursday. The other execution is planned in Texas.
Michael, 56, was sentenced to death after pleading guilty to the 1993 murder of Trista Eng, 16. The state pardons board rejected a bid for clemency on Wednesday.
Authorities say he grabbed Eng as she was walking home from her summer job at a fast-food restaurant in Dillsburg, Pennsylvania, drove her to a remote area, shot her three times and hid her body.
He was scheduled to be executed by lethal injection at 7 p.m. EST (midnight GMT) at a state prison in Rockview. Pennsylvania has not executed anyone since 1999.
The Third Circuit Court of Appeals ordered a 14-day stay in the execution. The Pennsylvania attorney general's office then filed an emergency motion with the U.S. Supreme Court to vacate the order.
The warrant for Michael's execution runs out at midnight, meaning it will not go ahead unless the high court rules by then.
Attorneys for Michael say he has Asperger's syndrome, a disorder that can cause sufferers to have trouble with social situations, be uncomfortable with changes in routine or have heightened sensitivities to certain situations.
The attorneys have tried to argue that Michael's disorder prevented him from accepting a life sentence he was originally offered.
In Texas, Mario Swain, 33, was convicted of murdering Lola Nixon, 44, during a 2002 burglary at her Longview home.
When Nixon returned home, he bludgeoned her with a tire tool, stabbed her and likely strangled her, according to an account by the Texas attorney general's office.
Swain put Nixon in the trunk of her car, drove her to a field and left her there barely conscious. He led investigators to an abandoned car with Nixon's body inside, the account said.
Investigators connected Swain to a truck parked on Nixon's street the night she went missing. Swain first accused two other men of the crime, but both had alibis.
Swain's execution by lethal injection is scheduled to take place after 6 p.m. CST (midnight GMT) at the state prison in Huntsville.
If it is carried out, Swain would be the 13th person executed in Texas this year.
Thirty-six inmates have been executed this year in the United States, according to the Death Penalty Information Center.
(Reporting by Corrie MacLaggan and Dave Warner; Editing by Ian Simpson, Ellen Wulfhorst and Mohammad Zargham)