S7E28: Smoke / Touch of Evil

A man is found dead outside in a vacant lot. Detective have no leads, no witnesses and the motive for the killing. Can the detectives track down suspects in time? Murder is always bad, but the murder of an innocent child drives detectives to work harder. When a young mother and her 10-year-old son are brutally stabbed and killed, detectives work against the clock to track killers.