- Anti-death penalty advocate says the state government "acted in sin"
- Witnesses say the inmate moved, seemingly tried to talk well after being given drugs
- The inmate, Clayton Lockett, later suffered what appeared to be a heart attack -- and died
- "The doctor observed the line and determined that the line had blown," an official says
(CNN)A vein on an Oklahoma inmate "exploded" in the middle of his execution Tuesday, prompting authorities to abruptly halt the process and call off another execution later in the day as they try to figure out what went wrong.