Brady Hartsfield grew up in an abusive, dysfunctional household with his mother, which deeply affected his psychological development. Isolated and emotionally neglected, he developed a lack of empathy and a growing resentment toward others.

As a young adult, he works at an electronics store, where his intelligence and technical skills allow him to appear normal and unnoticed.

In reality, he is the Mercedes Killer, responsible for deliberately driving a stolen car into a crowd at a job fair—an act he planned carefully and views in a disturbingly detached way.