Lily re-investigates a 1980's murder where a young housewife was blown up by a bomb in her backyard. Meanwhile, the victim's now-grown daughter is bothering a pervert whom she believes is the killer, but is he?
When a serial rapist sends a letter to the squad announcing his return to Philadelphia after five years, the team re-investigates the 1998 murder of a college student who was believed to be one of his victims.
A petty thief, hoping for a reduced prison sentence, relays information pertaining to the night in 1981 when a high school track runner was fatally shot, placing doubt on the guilt of the man now serving a life sentence for the crime.
After two years in a coma, a mother wakes in the hospital. Rosie hardly remembers the night she and her daughter were thrown out of a window, killing her daughter. Lily and Scotty look into the case and find a whole nest of bad secrets.
The team is searching for as suspected serial killer. The murders started with a young man who was hitchhiking home from the casino after winning $3000. They have little to go on other than a boot print.