Edward Lee Busby Jr. was executed by Texas Thursday night for the January 2004 abduction and murder of a 78-year-old woman. Photo courtesy Texas Department of Criminal Justice

May 15 (UPI) -- Texas on Thursday executed a 53-year-old man for the 2004 murder of an elderly woman, marking the state's 600th execution of the modern era, despite concerns that his intellectual disability should have barred him from being put to death.

Edward Lee Busby Jr. was administered a lethal injection at the Texas State Penitentiary in Huntsville. He was pronounced dead at 8:11 p.m. CDT, the Texas Department of Criminal Justice told UPI in an emailed statement.

Busby was executed for murdering 78-year-old Laura Crane on Jan. 30, 2004.

Court documents state that he and co-defendant Kathleen "Kitty" Latimer abducted Crane in Fort Worth, Texas. The pair robbed and then murdered the woman, who died of suffocation from having about 23 feet of duct tape wrapped tightly around her face.