An ex-con who spent most of his adult life behind bars on Thursday got what he said he wanted for robbing a suburban Chicago bank. The 74-year-old gets to go back to the place he called home—prison. Telling Walter Unbehaun he frightened a teller by showing her a revolver tucked in his waistband during the 2013 heist, a federal judge imposed a 3½-year prison sentence, citing a rap sheet that includes crimes from home invasion to kidnapping. “This is not the first time you’ve inspired fear,” Judge Sharon Johnson Coleman said, scolding the high-school dropout and part-time bathtub repairman. As...