Scanners Reference on The Flash (Episode aired 10/20/15)

Michael Ironside guest starred as a criminal. Early in the episode he gets pissed off at one of his henchmen, points an electronic device at him, the guy grabs his head in pain and drops to the floor. Later, the police find the headless body with traces of thermite around the neck and the detective asks "What kind of criminal explodes heads?"

Loved it.