The team reopens the 2003 triple homicide of Tom and Della Lincoln, a married couple who ran a popular diner and 17-year-old Derek Jackson, one of their employees when the prime suspect procures a viable alibi. Lilly and the squad find themselves immersed in gang culture as they search for the true killer in hopes of helping the victims' daughter find closure.

The team reopens the 1943 death of a female factory worker, 22-year-old Alice Miller which was originally ruled an accident when one of her former coworkers claims that her death might have been part of a cover-up.

The team reopens the 1979 murder of a 17-year-old runaway girl, Daniela after they receive a potential snuff film presumably featuring her murder. The team soon discovers that the young woman was transgender.

The team reopens the 1968 death of 24 year old Hank Dempsey, a prison inmate who was thought to have been murdered while escaping during Johnny Cash's performance at Folsom State Prison, after the discovery of human remains near the prison which contained the victims prison number. The investigation reveals however not only is the victim not who they thought he was, but also hidden corruption within the prison itself.

The team reopens the 1991 double murder of Sen and Channary Dhiet, married illegal Cambodian immigrants, after the victims' daughter stumbles on an Internet auction listing for her mother's gold bracelet. The team soon learns that the couple were keeping dark secrets from their daughter.

When a current investigation is discovered to be a copycat murder, the team reinvestigates the 1990 murder of Rita Baxter, a 12-year-old girl who was attending a slumber party the night of her death. The investigation reveals some disturbing secrets of potential suspects from abusive parents to teen drinking to even excessive bullying.

The team reopens the 1983 murder of 25-year-old Jeff Kern at the request of his former lover, an AIDS survivor, who hopes to find closure before his upcoming wedding. The team learns that the victim's relationship with his family and friends was strained due to his outspoken views on gay rights and the AIDS crisis.

A troubled man asks the team reopen the 1953 murder of his father, Elliot Garvey, a schoolteacher who was killed the same day that the Rosenbergs were executed, after learning that his mother lied about who he was. The team learns that the teacher was suspected of holding communist views due to his support for civil rights in schools and was slated to testify before the House Un-American Activities Committee shortly before his death.

The team begins the hunt for a serial killer when the reinvestigation of 31-year-old mother and wife Janet Lambert's disappearance in 1985 leads to the discovery of eight more victims, all of whom were found decapitated.

The team reopens the 1976 murder of Jerry Stone, a 24-year-old underdog boxer who died during a match after a referee on his deathbed confesses to have been paid to allow the match to turn deadly, but dies before he can give a name.

The team reopens the 1987 murder of Kayla Odoms, a 6-year-old girl who was killed in a drive-by shooting when the long-lost murder weapon is turned in as part of a gun buyback program. The team begins the daunting task of tracing the gun back to its previous owners in an effort to find the original shooter.

The team reopens the 1969 murder of 19-year-old Ellie McCormick after the number one suspect, a fugitive draft-dodger and her boyfriend, is arrested on his return from Canada. However, the team's investigation leads them down new avenues that suggest the boyfriend was framed, as well as the pressures of being drafted during the Vietnam War.

The team reopens the 1993 death of Colin Miller, a mentally disabled teenager who was hit by a train when drawings of his death are found next to his grave, implying he might have actually been murdered. The team learns that the victim had a turbulent home life.

The team reopens the 1998 murder of Kyle Bream, a 9-year-old boy who was kidnapped from a department store fitting room and later found dead in a lake, after Stillman's brother, a priest, recounts a dead man's confession related to the death. The team learns that the boy may have been a victim of child sex trafficking, and his death may be related to the more recent murder of a prominent businessman.

The team reopens the 1982 murder of Lindsey Chase, a troubled surgeon's wife who was killed in her home after her personalized ring is found on the finger of a dead junkie. The investigation may exonerate the victim's husband who claims he was wrongfully convicted of her murder, due to his troubled behavior.

The team reopens the 1995 death of 32-year-old Sloane Easton, a young mother and struggling alcoholic, whose death was ruled "accidental" after the victim's sister learns that a group of college students may have accosted her sister on the night of her death.

Haunted by a childhood memory, Jeffries asks Lily to help him reexamine the 1963 murder of Zeke Williams, a 16-year-old African-American boy who was found dead in an alleyway. When it is discovered his family had moved into a predominantly white neighborhood prior to his death, the team investigates the possible racial tensions surrounding his death.

The team reopens the 1985 murder of Joe Young, an optimistic young mill worker who was killed in an apparent mugging, after his nephew tells them that someone had come forward claiming to have stolen money off the victim's body. The team learns about how the mill closed down and the 26-year-old victim’s efforts to make a living for himself and his friends.

The team reopens the 1977 murder of Mike Cahill, a hotel doorman, in the hopes of linking a soon-to-be released serial killer to the murder in order to prevent him from walking free.

When an old truck containing human bones is pulled from the Delaware River, the team reopens the 1932 case of Billie Duccette, a missing 17-year-old girl who was presumed dead. The team discovers that the truck was owned by a Prohibition-era bootlegger and that the victim may have been involved in a forbidden love affair.

The discovery of nine human skulls leads the team back to serial killer George Marks whom they were unable to incriminate months earlier. When the detectives decide to reinvestigate the murder of his mother, 33-year-old Simone Marks in 1972, he emerges from hiding to face Det. Rush one-on-one where he is shot dead.