Případ Rigo: Ponožkový vrah (The Rigo Case: The Sock Killer) is a four-part true crime documentary series directed by Peter Bebjak. It follows the investigation into a series of murders that terrorized Bratislava in the early 1990s. The perpetrator was Slovak serial killer Ondrej Rigo, who targeted women living alone. His modus operandi involved breaking into their apartments, usually ground-floor flats, through a window at night. He would beat his victims to death with a metal bar or another blunt object found at the scene, before sexually assaulting their bodies after death.