Cold Case stars Kathryn Morris as Lilly Rush, the lone female detective in the Philadelphia homicide squad who finds her calling when she's assigned to "cold cases" -- crimes that have never been solved. Previously, she used her instinctive understanding of the criminal mind on current murders. Now, she's interrogating witnesses whose lives and circumstances have since changed, making use of today's new science and finding fresh clues to solve cases that were previously unsolvable, all of which appeals to this smart, driven detective. She's also prepared for the consequences: that her work will open up old wounds and may lead suspects to commit new crimes.
The 1994 case of a raped and murdered 16-year-old girl is re-opened when Det. Jeffries gets a call from a prisoner on death-row -- scheduled to be executed in just three days.
Rush and Valens re-open the case of a 25-year-old black woman, who was murdered in 1939, after the woman's granddaughter comes forward with new information. The woman was assumed to be a prostitute murdered by a client, but letters written by the victim indicate that she was afraid of a milkman.
The discovery of nine human skulls leads Rush back to George Marks, the serial killer she was unable to incriminate months earlier, and who walked away a free man. As the detectives reinvestigate his mother's murder from 1972, George is forced to emerge from hiding to face Rush again. This time, their very lives are at stake in their final showdown.
The 1999 drowning death of a military academy's swim coach, which was originally ruled as accidental, is reinvestigated after the homicide division receives a note that suggests it was murder. Back at the office, Valens searches for Elisa after she goes missing.
An HIV-positive gay man asks Rush and Valens to re-investigate the case of his dead partner who died of strangulation in 1983. Not only was the victim outspoken in his views about AIDS education within the 1980's secretive gay community, he was also the member of a very prominent family, disowned by his father for his sexual orientation.
The team re-opens the case of Matthew Adams, a teen-aged cult member who apparently committed suicide back in 1978, when his sister comes forth with new evidence about the deprogrammer her family hired to rescue her brother.
Lilly reopens a 1990 murder case, in which a prep-school girl was found dead in a local swimming hole, after a present-day victim with similar markings is discovered at the same place. The investigation reveals that the victim of the earlier crime was routinely tormented by a trio of classmates who invited her to a sleepover the night she was killed.
The team re-investigates the suspected 2007 murder of a bride-to-be who was kidnapped on the day of her engagement party. Lilly and Scotty travel to West Virginia to escort the prime suspect to Philly, and on their way back, they hear his side of the story.
The 1975 disappearance of an 8-year-old girl who was never found is reinvestigated after a note written by the girl shortly before she vanished turns up. Their friendship rattled many in the predominantly white neighborhood and the girls quickly became targets of hatred.
Det. Rush investigates the 1991 double murder of married illegal immigrants from Cambodia who were shot to death in their apartment and found by their 6-year old daughter. The now-teenage girl brings the case to Lilly after she discovers a bracelet once owned by her mother is for sale on the internet. The probe reveals that the parents had dark secrets unknown to their daughter.
The headless torso of a woman who disappeared in 1985, on the same day she filed domestic-abuse charges against her husband, is found by hikers in a wildlife preserve. The investigation quickly leads to the grisly discovery of 8 more decapitated bodies, the victims of a serial killer.
When a young woman, Rosie, wakes up from a coma, Lilly re-opens the fall in which her 6-year-old daughter Toya died. Things get complicated when the mother remembers very little of that night, and Lilly feels especially motivated to find the killer, as Rosie was poor and living on welfare, reminding Lilly of her own past, and giving her an emotional bond to Rosie.
The 1989 case of a woman murdered in front of her 3-year-old son is re-opened. A psychologist asks Det. Rush to look into the case again when the son, now a 17-year-old teen, suffers from intense nightmares and troubled behavior.
The 1991 death of an inner-city schoolteacher is reinvestigated when new evidence indicates she may have been murdered instead of dying accidentally during a carjacking that got out of control.
Lilly investigates the case of Daniel Holtz, a college baseball player who was found beaten to death in an alley behind a gay bar in 1964. Daniel's mother comes to Lilly in the hopes that his killer can be brought to justice before she dies. Lilly discovers the maltreatment gay victims received in the 60's, when her investigation discloses that it may have been a policeman's nightstick that made the lethal blows.