In 1961, Slivko witnessed a gruesome traffic accident in which a boy in his early teens who was wearing a Young Pioneers uniform was killed. The scene sexually excited him and he later recalled the accident vividly: the smell of gasoline and fire. Slivko quickly exploited his position at the children's club he ran to relive the fantasies of this accident: once or twice a year, he would form a close friendship with a boy usually aged between 13 and 17. The boy would be short for his age and would be wearing the Young Pioneers uniform (just like the boy in the traffic accident). Slivko would gain the boy's confidence and tell him of an experiment he knew which involved a controlled hanging into unconsciousness, to stretch the spine, after which, the boy was assured, Slivko would revive him.
Over the course of 21 years, Slivko persuaded 43 boys to take part in this 'experiment'. Once the boy was unconscious, Slivko would strip him naked, caress and fondle him, take films in which he would arrange the body in suggestive positions, and masturbate. In 36 cases, Slivko revived the boys and they, cautioned by Slivko into silence, got dressed and resumed their lives unaware just how lucky they were to survive.
In seven cases, however, Slivko's behaviour became violent. Once these victims were unconscious, Slivko dismembered their bodies, poured gasoline on their limbs and torso, and set the remains on fire to remind himself of the traffic accident which sparked his arousal. He usually kept the victim's shoes as a memento. As with his surviving victims, Slivko both photographed and filmed the entire process.