Sweet-looking boy grew up to be one of the most evil men on the planet

He was brilliant — undeniably so. But no one ever described him as warm.

Among classmates, he carried a nickname that said everything: a “walking brain.”

He played trombone in the school band. He skipped grades. He entered Harvard at just 16. To neighbors, his parents were the kind who “sacrificed everything they had for their children.”

By every outward measure, he had been handed rare gifts — and every opportunity to build an extraordinary life.

What he chose to do instead would horrify the world.

In 1942, a little boy was born in Chicago, into a working-class Polish-American family. His father made sausages for a living. His mother devoted herself entirely to her children, determined to give them every opportunity she never had

His parents were ordinary, working-class people. They were raised as Roman Catholics but eventually became atheists. In Evergreen Park, where their son grew up, neighbors remembered them as “civic-minded folks.” One neighbor said they “sacrificed everything they had for their children.”

He had a younger brother, David, someone who would one day play a crucial role in bringing his story to a close.

As a child, nothing seemed unusual. At Sherman Elementary, he was described as healthy, normal, well-adjusted.