Frank pushes to have a cop killer brought to justice, but Erin drops the charges and releases the suspect due to lack of evidence.
Famous movie star Russell Berke (Marc Blucas), who researched a role by shadowing Danny, becomes the victim of a stabbing.
Danny serves as lead hostage negotiator when Erin is held at gunpoint inside the courtroom; when Jamie is suspended for disobeying orders, Frank must determine a proper punishment.
A teen girl dies after she is seemingly pushed in front of a subway car by a homeless man; Frank is irritated by having to meet with the new inspector general (Bebe Neuwirth).
Danny and Baez think a girl has been kidnapped, but her mother denies it; Frank visits a priest who was arrested for a DUI.
Jamie's conduct is questioned when a suspect he was pursuing is fatally injured; Baez goes under cover to investigate a drug dealer -- the fiance of Danny's ex-girlfriend (Charisma Carpenter).
The community and the mayor scrutinize Frank's department when an officer is accused of using excessive force; a Wall Street executive who was deeply in debt is murdered.
Frank is put in danger when his dinner companion, mob lawyer Angelo Gallo, is shot; Danny is a juror in a murder trial.
Baez's estranged brother is the primary suspect in a homicide; a woman may have had a hand in her husband's death.
Danny and Baez meet with resistance while investigating a bombing; Frank deals with political fallout after a man punches an aggressive officer.
Danny's loyalty is tested when he has to investigate a childhood friend for possible ties to a mob family; Frank thinks a recent judicial ruling may be responsible for a rise in crime.
Danny tracks the distributor of a new, deadly type of heroin; Frank does everything he can to help Danny get the drug off the streets.
Danny and Baez search for a veteran who may have PTSD; a woman (Karen Allen) seeking justice for her murdered daughter catches Frank off-guard during a press conference.
A popular drag queen and reality-TV star is found dead in a park; the mother of an accused man abducts Erin.
A kidnapping investigation brings back bad memories for Danny, who worked a similar case years ago; Frank and Inspector General Peterson butt heads.
A woman threatening to kill herself and the man who murdered her parents calls Danny; Frank goes on Sean's class field trip.
Danny and Baez search for teenagers who have been punching unsuspecting people -- including a pregnant woman -- in the head; Frank worries that promoting an officer will be viewed as favoritism.
A woman is killed by a dose of lidocaine after a secret plastic surgery; Jamie is privately assigned a cold case; Erin decides to try speed dating.
A college professor involved with a questionable scholarship program is murdered; Danny is investigated for ethical and procedural violations.
Erin investigates a case involving a police officer accused of killing a suspect in custody; Jamie encourages Eddie to forgive her father.
When an undercover detective from Danny's precinct is killed, Frank learns the detective had a big secret; Eddie and Jamie help Nicky find a former classmate who is now homeless.