A mob informant returns to the city to testify in a case for Erin, and Danny and Baez are tasked with protecting him. Elsewhere, Frank and Mayor Poole get into heated negotiations regarding benefits for police officers.moreless
Danny and Baez look into the murder of a lower income resident living in a luxury building where a percentage of units are available for lower income housing. Frank disagrees with a detective friend of Gormley’s.moreless
When a homeowner shoots an intruder, Danny and Baez' investigation finds the intruder is a hitman. A 12-year old murder case of Erin's is reopened as an attorney tries to find justice for his mother.moreless
When a homeless teen claims his aunt was killed by her boyfriend, Jamie gets Danny involved. Erin is infuriated when McCoy replaces her on a case involving a corrections officer.
A robbery is committed by Army veterans, which leads to an internal struggle for Danny. Elsewhere, Garrett and Gormley clash over how to deal with the aftermath of a bomb scare created by a popular street artist.moreless
Frank is determined to find the evidence necessary to prosecute the killer who shot one of Henry's fellow officers many years ago. Danny and Baez investigate a rash of murders relating to adult film stars.moreless
Three community leaders are killed in apparent hate crimes, and Danny and Baez investigate as Frank meets with folks who want to ensure the gravity of these crimes is not ignored. Meanwhile, Linda wants to protect herself with a gun after getting mugged.moreless
When an officer's body camera fails during an exchange with a civilian, Frank must deal with the public's hostile response. Danny and Baez go to great efforts to protect an informant who's denied Witness Protection by the US Marshall Service. Erin looks into claims by a friend's daughter that she was raped at her high-status university.moreless
An on-air interview goes badly for Frank when he's blindsided by the interim district attorney. Elsewhere, Danny and his new boss deal with a drive-by shooting, and they take contrasting approaches to the investigation.moreless
Frank and Danny are intent on putting an international felon in jail, but he keeps evading charges. After researching college costs for Nicky, Erin thinks over going into private practice. Danny and his new boss butt heads.moreless
A woman's abusive boyfriend targets Jamie after he intercedes in a domestic dispute. Elsewhere, the press get ahold of an illegal tape capturing Henry's insensitive comments, and Frank must deal with the ensuing scandal.moreless
Frank has to choose between his son or the reputation of the police force after Danny is charged with using excessive force. After bringing a homeless man to the hospital, Eddie gets jealous when Jamie hits it off with one of the doctors.moreless
Danny and Baez temporarily get new partners because an outed cop's partner won't ride with him. Elsewhere, Jamie and Eddie try to snatch a collar from an arrogant detective; and Frank's statement on equality in the police force alienates the Archdiocese.moreless
Jamie refuses to shun a cop who testified against her partner, earning him disapproval from Eddie and other officers. Elsewhere, Erin and Danny get into a dispute when a closed case leads to a new murder; and a sports celebrity visits Frank.moreless
In the fifth-season opener, Baez gets injured while escorting confiscated drugs, so Danny goes after the drug cartel responsible. Elsewhere, a lieutenant with a commendable record engages in controversial behavior, putting Frank in a difficult situation.moreless
For the season four finale, Danny's investigation into an off-limits case gets him placed on modified duty. He then realizes he's uncovered information that someone wants to keep hidden which he passes on to Frank. Frank becomes concerned with the sheer size of the case and how far it reaches internally.moreless
An undercover cop in Danny's squad gets killed, and Frank is determined to find the murderer. However, things get complicated when the victim's secret is unearthed. Elsewhere, Nicky turns to Jamie as she looks for an ex-classmate living on the streets.moreless
A cop is accused of killing a suspect already in custody, and Erin gets assigned the case. Elsewhere, Jamie tries to convince Eddie to reconcile with her dad.
The murder of an esteemed college professor caught up in a dubious scholarship program is investigated by Danny and Baez. Danny finds out he's being investigated by the District Attorney for ethical and procedural violations.moreless
Danny and Baez' latest investigation involves a woman whose body was dumped after plastic surgery. The M.E. finds the cause of death to be a lethal dose of fentanyl. Frank asks Jamie to examine a cold case. Erin decides to try speed dating but ends up going against someone in court that she met at the event.moreless
Danny and Baez investigate when the latest victim of a "knockout game" is an expectant mother. Frank struggles with a decision to promote an officer after he determines it might look like he's giving the officer preferential treatment.moreless
When a woman calls in threatening to kill the man who killed her parents, along with herself, Danny must race against time to find her. Frank goes along with Sean on a class field trip and does his best to get the chaperone to let the kids have some fun.moreless
The current case of a kidnapped girl brings back memories of a similar unsolved case that Danny worked on years ago. Frank and Kelly Peterson are at odds about disclosure of information on a program that lets Frank direct intelligence officers overseas.moreless
Danny and Baez look for the killer of a popular drag queen found murdered in a local park. After she's kidnapped by an accused drug dealer's mother, Erin reexamines the case.
Danny and Baez search for a Marine veteran with PTSD. A woman seeking justice for her daughter who was murdered approaches Frank at a press conference.
Frank and Danny go after the distributor of a deadly new brand of heroin.
Danny must investigate his childhood friend, Mickey, who's come under investigation for having ties to a well-known mob family. The results of a recent judicial ruling regarding the legal status of "stop and frisk" indicate a rise in crime.moreless
Danny and Baez get resistance from the community while investigating a local bombing. After a man punches out an officer during questioning, Frank is left with the political fallout.
Danny and Baez's homicide investigation establishes her estranged brother, Jave "Tic-Tac" Baez, as the main suspect. Frank investigates police brutality complaints against a German Shepherd in the K9 unit. Henry checks out the widow of a former police pal when he suspects she might have had some responsibility for his death.moreless