When Hale DeMar shot an intruder in his house, he may well have saved his children’s lives. So why was he charged with a crime? On the night of Dec. 29, 2003, Morio L. Billings was AWOL from the Army, in violation of his probation, and driving a BMW X5 sport utility vehicle he’d stolen less than a day earlier. The 31-year-old was staying with his mother in Chicago, but he wanted “blow and crack” badly enough to risk yet another jail stay. He had been taken into custody at least six times in 2003, with police alleging residential burglary,...