When an armed robbery ends with the death of a police officer, Frank makes it a mission for the NYPD to bring the suspect to justice. However, tensions run high in the Reagan household when Erin drops the charges and releases the suspect due to lack of evidence.
When Danny and Baez suspect a little girl might be the victim of a kidnapping, the girl’s mother denies it, but her story doesn’t add up. Meanwhile, Frank pays a visit to a priest, a counselor to the NYPD, who was arrested on a DUI charge.
When an officer is accused of using excessive force on a suspect, Frank finds his department under scrutiny from the community and the mayor. Meanwhile, Danny and Baez investigate the murder of a Wall Street securities trader who was deep in debt due to a gambling addition.
Danny and Baez investigate a homicide in which Baez’s estranged brother, a former drug addict, is the lead suspect. Meanwhile, Frank learns one of his most highly decorated officers, a German Shepherd in the K9 unit, is being accused of police brutality, and Henry investigates the widow of a former NYPD pal who might have had a hand in her husband’s death.
Danny and Baez investigate a local bombing, but meet with tension and resistance from the community during the investigation. Meanwhile, Frank must deal with the political fallout when a man punches an officer who was overly aggressive in his questioning.
Danny’s loyalty is tested when he is assigned to the case of a childhood friend, Mickey, who is under investigation for having ties to an infamous mob family. Meanwhile, Frank gets word that crime is on the rise due to a recent judicial ruling about the legality of the “stop and frisk” policy.
When Danny takes a call from a woman who is threatening to kill herself along with the man who killed her parents in a drunk driving accident, he rushes to find her. Meanwhile, Frank accompanies his grandson, Sean, on a class field trip and struggles to get the lead chaperone to loosen the reigns so the kids can have fun.
A woman dies after undergoing a secret plastic surgery, so Danny and Baez try to figure out what happened. Elsewhere, Frank asks Jamie to solve a cold case; and Erin explores the world of speed dating.
After a detective from Danny's precinct is killed while working undercover, Frank goes above and beyond to find the killer only to discover that the victim held a big secret; Jamie and Eddie help Nicky track down a homeless former classmate.