Danny and Baez investigate the reappearance of a runaway, who isn't quite who she seems. Frank battles with the mayor about a community parade that is honoring a once convicted cop bomber. Jamie and Eddy stumble upon a misleading congressman.
A detective in a mob case is killed. Garrett is accosted outside his home by a SWAT team after a false report. Erin is approached by an acquaintance of Anthony who offers to help in an organized crime case over Anthony's objections.
Cases of the week include (Frank) prison riots due to a social experiment the mayor is trying, (Jamie) an 18 year old that overdoses, and (Danny) a wife and mother found murdered in her home.
When a famous basketball player is found dead in his apartment of an apparent drug overdose, Danny looks into ties to old friends in a local gang. Erin is forced to re-examine the case of a man she convicted years ago who may be innocent.
Cases this week involve (Danny) a widowed nurse that is the victim of domestic violence, (Frank) a woman that alleges corruption at the jail, and (Jamie/Janko) an illegal alien that gives birth and lives in a condemned home.
Eddie's judgment is clouded by her past when she arrests a loathed college acquaintance; Frank is hesitant to mar the spotless record of a member of the force who tested positive for marijuana.
Danny and Baez join a narcotics task force to track a drug supplier; Baez comes into contact with drugs and gets an accidental overdose; Jamie and Eddie work to protect a rehabilitated sex offender; Frank forms an unlikely alliance with Mayor Dutton.
Jamie and Eddie ask Erin to drop the charges against a man who bravely rescued a woman from a local hostage situation; Danny and Baez work a case involving car thieves and discover the leader is a mobster they've dealt with before.
When a journalist disappears while working on an exposé about an innocent man serving time for murder, Danny and Baez hope that re-examining the original case will help them find her.
When Henry is the key witness on Danny and Baez's case, his meddling eventually leads them to valuable information. Nicky shocks the family by siding with an activist friend of hers. Jamie and Eddie learn a parole officer is taking advantage of his power.
A student is shot by a rival gang member in his high school courtyard. Danny and Baez try to prevent further violence. The principal recklessly takes matters into his own hands.
A man living a double life with two separate families is murdered; Erin asks Anthony to help investigate his former partner; Frank deliberates between two candidates for the chief of transit position.
Danny forces his brother-in-law to help Baez take down the mobsters he's mixed up with; Frank suspects his old partner is guilty of a crime; Jamie is approached by an officer who wants help getting reassigned from his undercover assignment.
A woman voices outrage over her son's unsolved murder and Danny re-examines the case. Eddie is shot while on duty. Erin and her ex-husband face off in court. Frank deals with an angry police force after the mayor fails to defend it.
Danny and Baez race to find a girl who will die without her medication; Jamie and Eddie are on the wrong side of an investigation after engaging in a car chase; Sean wins an essay contest.
Danny is forced to ask his incarcerated arch enemy for help when a convict escapes from prison; Frank tries to talk Jamie to take the sergeant's exam; Erin's plan to go on a date with her ex-husband creates friction between her and Anthony.
Frank goes head-to-head with a data-tracking company when they refuse to unlock the phone of a terrorist that may hold information regarding upcoming targets.
