Attorneys for a condemned Missouri man say the state's execution protocol allows for “surgery without anesthesia” if the typical process of finding a suitable vein to inject the lethal drug doesn't work.

For decades, Missouri executions played out in similar fashion: An inmate was strapped to a gurney in a drab room, alone except for the eyes of witnesses staring through thick glass as unidentified executioners administered the lethal chemical from behind a cinderblock wall.