Rush's instinctive understanding of the criminal mind and her singular passion for uncovering the truth makes her the perfect fit for investigating cold cases, yester-crimes that have remained unsolved – some only a few months old, others going back decades.
The team reinvestigates the 1983 murder of 25-year-old Dana Deamer, a young wife and mother who was killed in an explosion outside her own house while picking up what was supposed to be a box of laundry detergent shortly before she was to testify in court against a man who indecently exposed himself to her in public.
The team reinvestigates the 1998 murder of 21-year-old college student Gail Chimayo when her killer, a serial rapist who has been inactive for the past five years, sends them a letter announcing his return to Philadelphia and his intentions.
When a drug addict brings in an audio tape capturing the recording of a fatal shooting, the team reopens the 1973 murder of a young police officer, 21-year-old Joe Washington, who was killed after responding to a call at a drug-infested housing project.
A woman asks Lilly to reinvestigate the unsolved murder of her son Daniel Holtz, a 21-year-old former college baseball player, who was beaten to death outside of a gay bar in 1964 after it was discovered that he was homosexual.
The team reinvestigates the 2001 death of 6-year-old Toya Miles, who died after falling through her bedroom window, along with her then 23-year-old mother, Rosie, who survived, but suffered severe head trauma, putting her in a two-year coma.
When Lilly receives an anonymous phone call from a man who claims to have killed an elderly woman in 1989, the team investigates the disappearance of Krystal Hogan, an 81-year-old grandmother who went missing that same year.
Lt. Stillman asks Lilly to reinvestigate one of his first cases as a homicide detective: the 1980 murder of 8-year-old Timothy Barnes, who was knocked out and left on the snowy ground and died tragically of hypothermia.
Human remains found during a building demolition prompt the team to investigate the unsolved 1969 double murders of 22-year-old Julia Hoffman and 23-year-old Gerald Gary, two hippies who belonged to a group that facilitated access to illegal abortions.
The team reinvestigates the 2000 murder of 39-year-old Greg Cardiff, a husband and father who was killed in a hit-and-run accident just a few minutes into New Year's Day, after a recovering alcoholic comes forward as the possible culprit.