A Baltimore mom came home from a 12 hour work shift to find her 15-year-old daughter shot and killed in her own bed, and her 9-year-old son shot and killed in the hallway. It took a few weeks, but police now say they have their killer in custody: a 16-year-old boy who had apparently only recently begun to talk with her daughter. We go over the mountain of evidence that led police to the teen and a warning from the police chief for every parent.