Anatoly Yuriyovych Onoprienko (Ukrainian: Анатолій Юрійович Онопрієнко; Russian: Анато́лий Ю́рьевич Оноприе́нко, Anatoly Yuryevich Onoprienko; 25 July 1959 – 27 August 2013) was a Soviet and Ukrainian serial killer and mass murderer. Known by the nicknames The Beast of Ukraine, The Terminator, and Citizen O, Onoprienko confessed to killing fifty-two people upon being apprehended in April 1996.