A Virginia man scheduled to be executed next week for the gruesome killing of his former girlfriend has asked the U.S. Supreme Court to consider his appeal.

Dexter Lee Vinson, 42, is scheduled to die on April 27 for the 1997 capital murder of 25-year-old Angela Felton in Portsmouth. The mother of three was abducted and taken to an abandoned house, where she was sexually mutilated and stabbed. She bled to death.

In a petition filed with the Supreme Court this week, Vinson's attorneys argue there is ample evidence--including questionable eyewitness testimony--to suggest that Vinson was not the killer. The attorneys also accuse the prosecution of withholding evidence that would have cleared their client, including notes from an interview with an eyewitness who said she saw the killer at the crime scene at the same time Vinson was at his job in Williamsburg.

"This Court should not let the execution go forward while so many disturbing factual conflicts remain unresolved," Vinson's attorneys wrote in the petition.

According to a 1999 Virginia Supreme Court ruling, witnesses saw Vinson in the vicinity of the vacant house where Felton's nude body was discovered wrapped in a blanket.

Physical evidence, including a palm print and DNA, linked Vinson to the crime. A federal judge has dismissed Vinson's petition for a stay of execution after Vinson challenged Virginia's method of lethal injection. U.S. District Judge Henry E. Hudson ruled that nothing has changed since he upheld the state's lethal injection procedures in the case of James Edward Reid, who was the last Virginia inmate executed in September 2004.