Detective Jane Rizzoli and medical examiner Maura Isles investigate the grisly murder of a wealthy couple. The M.O. matches the work of a serial killer known as the Surgeon, who once nearly murdered Jane. Now that the Surgeon is behind bars, it seems one of his proteges is picking up where he left off.

Tensions are high as the squad investigates a possible copycat of the legendary Boston Strangler…or could it be the Boston Strangler himself? Meanwhile, Jane butts heads with her new boss, Lt. Grant, who just happens to be from the same neighborhood where Jane grew up. And Maura gets into trouble with her habit of diagnosing everyone – including her date.

Jane was once abducted and neared killed by imprisoned serial killer Charles Hoyt. Now a body found in a park has all the indications of being his work. Jane must do her best to keep her fear of this man in check while Maura attempts to get inside the mind of the killer.

After an undercover cop working a narcotics-smuggling sting is shot dead, the killers next turn their sites on Boston homicide headquarters, leaving Jane, Maura and Frankie Jr. trapped in a fight for survival on their home turf. It's a situation that will force Maura to challenge herself like never before. On the home front, Jane's parents are excited that their oldest child, Tommy, is being released after serving time in prison.

After taking a bullet in the Season Finale during a siege of the precinct, Jane Rizzoli is honored as a hero at a public event. The celebration is short-lived, however, when disaster strikes. The ensuing case reunites Jane with an old high-school flame, Sgt. Major Casey Jones, who may be just the person she needs to heal her emotional scars.

Jane and Maura investigate after the coach of the Boston Pilgrims baseball team is found dead in the locker room. The death comes as a star player and the team owners battle for control of the team. Meanwhile, Jane's brother Tommy returns home after being released from jail.

A serial killer claims to have clues about the murder of another prisoner; Frankie Jr. prepares to take the detectives exam.

The shooting of a community activist brings out a witness who's willing to testify. TV host Bill O'Reilly airs his disapproval of the police department.

The world of competitive dance turns deadly when the mother of a star performer is stabbed to death at a competition. Jane and the team search for clues, but they soon realize something is off about the woman’s history. Korsak has his hands full when his stepson is accused of shooting a cop. Guest star Lolita Davidovich returns as Korsak’s ex-wife Melody.

When a warehouse fire kills a firefighter, Jane and Maura must investigate whether it was arson or an accident. But the investigation hits a snag when a hit-and-run leaves someone in the hospital. Guest star Billy Burke returns as FBI Agent Gabriel Dean, who hopes to rekindle his relationship with Jane. And guest star Jacqueline Bissett reprises her role as Maura’s mother, Constance Isles.

Jane and Maura’s friendship suffers following the shooting of Maura’s biological father, gangster Paddy Doyle. Jane also finds herself in the middle of an Internal Affairs investigation. And her relationship with Agent Dean is exposed.

Young female professionals dressed as dolls are turning up dead on the public transit system, and Jane and Maura must piece together the clues. Angela implements new ideas for the café. And Jane learns more about how Casey was injured.

Jane looks for a way for Maura to meet her biological mother, Dr. Hope Davis. Angela gets involved in a political campaign. And a nun from Jane and Frankie Jr.’s past returns.

When a rich financier is found stuffed in a trashcan wearing a cloak and mask, Jane and Maura must figure out what happened. Meanwhile, Maura makes a deeper connection with her biological mother, Dr. Hope Davis, and half-sister, who still doesn’t know Maura is related to them.

A boy band star returns to his roots for a show and winds up murdered. Jane and Frankie, who grew up with the victim, work hard to solve the case. Meanwhile, Jane and Maura must decide if it’s time to tell Angela the truth about Lydia’s pregnancy just as Angela prepares to throw her a baby shower.

When a statue breaks open to reveal a dead woman inside, Jane and Maura must find the killer quickly as the body count begins to rise. Back at headquarters, a new homicide detective is named to the squad. Meanwhile, Dennis Rockmond returns to Boston after disappearing on Maura and tries to woo her back. Lydia goes into labor.

A community parade turns deadly in a case that brings family tensions and politics to the forefront. Maura, who is dealing with her own family issues, is not quite herself. And a surprise visit from Lt. Col. Casey Jones reveals some shocking news.

Jane is unhappy when a former colleague returns as the new lieutenant of the drug unit; a tip from Cailin causes Maura to investigate Hope.

A popular high school teacher is killed in a hit and run that is clearly no accident. The squad works to solve the case, but Jane is preoccupied with Lt. Martinez’s apparent favoritism towards his own drug unit.

The squad rushes to solve a violent homicide case muddied by conflicting evidence. Maura is burdened with the major decision of whether to take in her recently paroled grandfather. Meanwhile, Jane and Casey are forced to decide between their careers and their romantic relationship.

A senator's daughter is found murdered; Tommy begins to slip back into old habits; Jane reveals some shocking news.