More than 20 years have passed. Pavel, then 18, spent seven years in prison and five years in a psychiatric institution. During his last year in prison, he asked to be surgically castrated. Having his testicles removed, he said, was like draining the gasoline from a car hard-wired to crash. A large, dough-faced man, he is sterile and has forsaken marriage, romantic relationships and sex, he said. His life revolves around a Catholic charity, where he is a gardener.

“I can finally live knowing that I am no harm to anybody,” he said during an interview at a McDonald’s here, as children played loudly nearby.