People naturally open their doors when someone on the other side knocks or rings the bell. We naturally trust people. It’s built into our DNA until someone compromises that trust, but until they do, we open the door.

Ten years of marriage, shared visitation with one stepchild and two children after a divorce can leave a man lonely.

In 2005, a 36-year-old man worked at his family’s restaurant. In 2007, he was on trial for breaking into a young woman’s home. The...