The sixth season ends with the investigation of a female cadet's 2005 murder at a local military academy, where she was resented for being the first female cadet. The case dredges up unpleasant memories for Lilly, who recalls her own difficult journey to become the first female homicide detective in Philadelphia.

The 2005 murder of a local military academy's first female cadet is investigated after her body is discovered in a buried foot locker. The probe reveals that the victim was cruelly treated by resentful male cadets and school administrators, as well as hateful alumni.

The 1963 shooting death of a wandering pool hustler is reinvestigated when the murder weapon is discovered at a pool hall during a renovation. The probe reveals the victim played there just days before he died and that he was gunned down on the same day President Kennedy was assassinated.

The 1999 murder of a former Cuban baseball star who escaped to the U.S. to pursue a major-league career and provide for his family is reinvestigated. The probe reveals that the Cuban government took drastic action against him for speaking to a U.S. sports agent. Meanwhile, Lilly's department plays its annual softball game.

The 1958 murder of a newlywed real-estate developer who pioneered the lucrative idea of developing suburban communities with affordable houses is reinvestigated when new evidence suggests that he wasn't killed where his body was found. Also: Lilly dines with her father.

A psychiatrist's 2004 death is reinvestigated to determine if one of her patients killed her by arson. Damaging notes from the suspect, now homeless and a paranoid schizophrenic, fuel the reexamination.

The team take a break from digging up past crimes when Agent Jeffries is shot. Can they put their emotions aside and catch the escaped gunman?

The team reopen a 1976 murder case when new evidence suggests the 17-year-old victim had connections to a notorious motorcycle gang.

The detectives tackle a dual investigation, chasing leads on a missing teenager and his murdered father. Both were embroiled in a murky mob affair.

The team investigate the 1967 demise of a brush salesman privy to private information about the residents in his area.

he 1988 murder of a reporter is reinvestigated when previously unseen TV footage indicates she was gathering evidence against a plastics company whose employees were being exposed to dangerous levels of asbestos. Her primary source for the information was an employee of the company.

The 2007 murder of an auto mechanic who won $8 million in the state lottery is reinvestigated. Meanwhile, the evolving relationship between Valens and Frankie hits a major roadblock.

The 1960 murder of a stewardess who was attempting to organize a union is investigated, and the probe uncovers several hostile suspects who strongly resented her.

Reinvestigating the 2005 murder of a black politician who vowed to rid his old neighborhood of drug dealers.

The 1953 murder of a famous pinup girl is reinvestigated when a fan brings in a crime-scene photo that sheds new light on the case.

The 1989 murder of a Russian opera prodigy who defected with her family to the U.S. before the fall of the Berlin Wall is reinvestigated. The case has significance for Vera because he was a rookie cop at the time and remembers the family seeking political asylum at the police station.

The 1969 murder of a 12-year-old boy is reinvestigated when new evidence is discovered by the police officer who originally worked the case. The probe begins after a toy rocket with the victim's name on it is given to the now-retired cop who handled the investigation.

The 1981 murder of a single mother who disappeared is investigated when her body is found in the trunk of a car. The probe reveals the victim worked at a run-down car dealership and that several of her coworkers resented her.

The 1951 murder of a marine who was reported AWOL on his last night of shore leave is reinvestigated. The new probe reveals that the victim was defending a fellow soldier on the night of his death.

The 1978 death of a teen roller skater who was found in a ravine is reinvestigated when a new witness comes forward.

Will and Kat travel to Mississippi to investigate the 1964 death of a Philadelphia woman who was secretly involved in helping bring supplies to the state's Freedom Schools, which educated black children. The victim's body was discovered in Pennsylvania. She was thought to have been involved in a hit-and-run accident, but new evidence, including a threatening letter, points to murder.

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.

The sixth season begins with the reinvestigation of a college-football star's murder in 1973 on the eve of a championship game. The unsolved case is reopened when new evidence suggests he was killed earlier than previously assumed. The probe also reveals the victim may have been involved with steroids.