The team reopens a brutal 1994 triple-murder case in which three young boys, 10-year-olds and best friends Jack Raymes, George Russo, and Sean Costley, were all murdered when the mother of one of the two teenagers convicted of the crime comes forward with evidence that they were innocent. The investigation uncovers major errors made by the original investigation from inconsistent evidence to overzealous officers making questionable choices.
Song featured in the intro: "All Apologies", by Nirvana.
After a piece of clothing belonging to a murder victim is found in an old van, the team reopens the 1998 murder of Carrie Swett, a 15-year-old girl who had a reputation for being promiscuous. The investigation leads the team to a religious club where they learn a dark secret that could prove to be the key to solving the case.
When the younger sister of a missing person comes to the police for help, the team reopens the 2006 case of Anna Gunden, a 16-year-old Amish girl who was murdered while she was in Philadelphia experiencing the Amish rite of passage called "rumspringa".
The team reinvestigates the 1953 case of Bingo Zohar, a talented 19-year-old rock'n'roll singer when new evidence comes forth suggesting he wasn't killed in the place where his body was found. The investigation reveals that the victim was facing discouragement and bullying from his peers and family over his musical aspirations.
Song featured in the intro: "Dimples and Cherry Cheeks", by The Andrews Sisters.
The team reopens the unsolved 1989 case of an unidentified Jane Doe, Margot Chambers, when she dies in the hospital after being comatose since the day she was shot 18 years ago, only to encounter a long list of suspects when they learn that the woman was a professional grifter who had swindled dozens of people and now have to solve which of her victims was the most motivated to kill her.
The team reopens the 2002 murder of Terrence "T" Carter, a 14-year-old social outcast from the wrong side of the tracks, after it's discovered his mother had been using his social security number since his death. The team discovers that he was a prodigy with numbers and his talent may have led him to dangerous territory.
When human remains are discovered in the bottom of a well, the team opens the 1938 case of a 33-year-old housewife, Audrey Metz, who went missing the night of Orson Welles's radio broadcast of The War of the Worlds.
When the body of a newly missing boy, 12-year-old Shemar Reynolds, is found in a cargo container, the remains of three other victims, 12-year-old Damont Henderson, 9-year-old Kendrick Malone, and 14-year-old Marcus Hollister, who vanished from 1999 to 2003 are found. The team realizes they're dealing with a serial killer and must figure out his M.O. before he strikes again.
The team reinvestigates the 1963 death of Samantha Randall, a 16-year-old tomboy whose death was ruled a suicide, after new evidence suggests that she may have been murdered for acting and dressing like a boy. The team discovers that her own father sent her to a hospital for "gender deviants."
The team reopens the 1982 murder of Mike Delaney, a popular 22-year-old college valedictorian who was shot to death on the day of his graduation, after "RAPIST" is spraypainted onto his grave. The team discovers that the young man was a serial rapist, whose victims were rebuffed when they sought help.
The team reopens the 1945 murder of Ray Takahashi, a hardworking Japanese-American family man who was killed outside an Army-Navy football game. The team learns that the original investigation may have been incomplete after they discover that the victim and his family were among the thousands of Japanese-Americans who were sent to WWII internment camps.
Song featured in the intro: "Boogie Woogie Bugle Boy" by The Andrews Sisters.
Song featured in the finale: "Billy's Letter" by David Huynh.
The team searches for a serial bomber whose latest pipe bomb maimed the wrong target and whose three previous bombings, in 1999, 2001 and 2003, collectively blinded a man and killed two others.
The team reopens the 1998 murder of a 17-year-old girl, Tamyra Borden, after her father is arrested for beating his stepdaughter. The team discovers that the victim became entangled with a group of neo-Nazis who were suspected of another unsolved murder around the same time.
After traces of blood linked back to a missing teen are found, the team re-investigates the 2006 case of Andy Rierdan, a 17-year-old boy who went missing from a high school for the deaf. The investigation soon reveals the victim's efforts to be able to hear again, much to dismay of his friends and family.
Lilly and Scotty travel to West Virginia to escort a suspected murderer who is believed to have abducted a woman, Brenda McDowell, from her 2007 engagement party and then killed her, back to Philadelphia. Now, as they drive back to Philadelphia, they must listen to his clues and his motives after they find out that the last victim is possibly still alive.
The 1997 case of Pete Doyle, an ex-con who went missing after having been released from prison, is reinvestigated when the victim's decomposed severed hand is discovered in a crack house during a drug bust. To solve the case, they must discover if the victim had gotten back to his old habits, or if he was killed trying to protect his estranged son.
The team reinvestigates the 1962 death of Nancy Patterson, a 27-year-old housewife and budding writer whose death was ruled a suicide, after it is revealed that her suicide note does not match her handwriting. The team soon learns that the victim was acting paranoid shortly before her death, but a shocking discovery turns the case upside down.
Priscilla Chapin, a former drug addict whose son, Max, was seemingly killed in an apartment fire in 2005 comes forth claiming she just saw her child in the park. The team must re-examine the original crime scene to see if the boy could have been abducted during the fire and if so, who really started the fire.
Song featured in the intro: "Better Days", by Goo Goo Dolls.