A senator's daughter is found murdered; Tommy begins to slip back into old habits; Jane reveals some shocking news.
When a food truck chef dies suddenly, all signs point to poisoning; Tommy announces some big plans; Maura's birth mother tries to make amends with her daughter.
A musician is stabbed in a bar; the squad realizes that the stabbing victim had something to hide; Jane's father returns with shocking news.
A kidnapper dressed as a clown re-emerges after 20 years; Jane's relationship with Casey grows more serious; Maura inadvertently gets in the middle of another relationship.
The squad tries to solve a homicide case that is muddied by conflicting evidence; Maura must decide if she is going to take in her recently paroled grandfather; Jane and Casey must decide between their careers and their relationship.
A mock trial advisor dies during a competition; Jane is concerned that Angela may be hiding financial issues; Tommy hires a lawyer to settle his claim against the Storrow Center.
The squad investigates when an amateur drag race turns deadly; Jane turns to Lt. Martinez for help and he seems to be thwarting her investigation.
Jane and Maura are asked to present the case of a serial killer at a symposium for law enforcement; Jane and Maura make a discovery.
Frankie Jr. is brought in to help with a murder case involving a youth hockey league; Cailin asks to stay with Maura; Maura has trouble living with a teenager.
A popular high-school teacher is killed in a hit and run; Jane is preoccupied with Lt. Martinez's apparent favoritism toward his own drug unit.
A viral video of Jane jeopardizes her career and reputation; the squad tries to solve a murder case involving a conspiracy theorist.
Maura gains insight into her father; Korsak opens up about Cavanaugh's tragic past; Maura and Jane unravel a shocking secret about Paddy and Hope.
Maura becomes a murder suspect when her date is found dead and she can not remember their evening together; Jane struggles to protect her best friend while doing her job.
A body is discovered in the church at TJ's christening; Jane almost abuses her power to protect Tommy; Lydia's fiancé threatens to take custody of TJ; budget cuts cause tension at the department.
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 community parade turns deadly; Maura does not seem like herself; Lt. Col. Casey Jones reveals some shocking news.
