A politician, a children's clown, a party host, an entrepreneur, a father and a husband: all roles played by John Wayne Gacy to mask his true nature - that of the world's most notorious serial killers in history.
Like the fictional character in Robert Louis Stevenson's novel, Dr. Jekyll and Mr. Hyde, Gacy somehow managed to live a secret life between the best of good and the worst of evil. By day, he was a model citizen. By night, he would become overwhelmed by a seething rage and sexual attraction to teenage boys.
Watch on Sunday 18 April at 10pm
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