HUNTSVILLE, Texas (AP) — A man who experts for both prosecutors and defence attorneys had said was intellectually disabled became the 600th person executed in Texas since 1982, put to death Thursday evening for the killing of a 77-year-old retired college professor.

Edward Busby Jr was pronounced dead at 8:11 p.m. following a lethal injection at the state penitentiary in Huntsville, hours after the U.S. Supreme Court lifted a stay over his disabilities claims. The execution capped a series of last-minute legal efforts by Busby's attorneys seeking to spare his life.

Busby was condemned for the suffocation death of Laura Lee Crane, a retired professor from Texas Christian University. Prosecutors said she was abducted from a grocery store parking lot in January 2004 and left to suffocate in the trunk of her car with duct tape wrapped heavily around her face, covering her mouth and nose.