| No. overall | No. in season | Title | Directed by | Written by | Original release date | Prod. code | U . viewers (millions) |
| 55 | 1 | "Life and Death" | Bill Roe | Alexi Hawley | September 26, 2021 (2021-09-26) | 401 | 3 |
| In the midst of Lopez's kidnapping, Jackson is killed by La Fiera's men while trying to save her. Grey and Wesley enlist the help of the DEA, but they are bound by the political ramifications of the case. Nolan, Tim and Harper enlist Max, who gives them a helicopter and arms to rescue Lopez, who has been brought to Guatemala. Wesley receives help f |
| 56 | 2 | "Five Minutes" | Lisa Demaine | Brynn Malone | October 3, 2021 (2021-10-03) | 402 | 3 |
| Tim is promoted to Sergeant and leads the roll call as a new rookie, Aaron Thorsen, is handed to Harper. Harper is convinced Aaron does not have what it takes to become a cop, as he is suffering from memories of his trial for having allegedly murdered his roommate in Paris. However, Aaron takes on the courage to be motivated to become a cop, convin |
| 57 | 3 | "In the Line of Fire" | Daniel Willis | Robert Bella | October 10, 2021 (2021-10-10) | 403 | 2 |
| Nolan and Lucy respond to a house fire and rescue a man trapped inside. The LAFD discovers a body inside after the fire is put out; an autopsy reveals that he was killed before the fire occurred. While on a break, Nolan, Lucy, Tim, Harper and Webb witness a sniper shooting at a private escort vehicle. The sniper escapes, and Harper and Aaron discov |
| 58 | 4 | "Red Hot" | Lisa Demaine | Diana Mendez Boucher | October 17, 2021 (2021-10-17) | 404 | 2 |
| Lopez returns to work, while Nolan investigates an alleged home dispute where a wife has escaped from her husband's house. Nolan later finds the woman, Linda Charles, walking in an alley, disoriented and speaking a foreign language. The husband and his assistant arrive and pull guns on them as Nolan's suspicions are heightened. All three of them ar |
| 59 | 5 | "A ." | Daniel Willis | Zoe Cheng & Paula Puryear | October 31, 2021 (2021-10-31) | 405 | 2 |
| Halloween in Los Angeles has Nolan and Harper detaining a crazed person in a park, in what initially seems like a zombie attack. They learn at the hospital that the woman took a drug, Bomb-X. Lucy assists a neighbor with two ghost hunters who wants to charge her more money than what she can afford. Lopez is handed the case, but the victim, Mrs. Cro |
| 60 | 6 | "Poetic Justice" | C. Chi Yoon Chung | Bill Rinier & Natalie Callaghan | November 7, 2021 (2021-11-07) | 406 | 2 |
| Tim is tasked by Grey to talk veteran officer Jerry McGrady into retiring, and Tim decides to take Jerry with him on patrol. Nolan, Lucy, and Harper start investigating a treasure hunt, based on a cryptic poem which Nolan and Harper found with a suspect. Tim and Jerry join the hunt, as evidence from an old case worked by Jerry proves to be connecte |
| 61 | 7 | "Fire Fight" | Tori Garrett | Corey Miller | November 14, 2021 (2021-11-14) | 407 | 2 |
| Bailey is severely injured in the explosion and has to use crutches. Lopez, Nolan, and Harper reopen the serial arson investigation after a colleague of Bailey reveals that Fred was in the hospital in Nevada at the time of the murders. They also conclude that the real killer was trying to frame him. Tim and Lucy investigate several cases of alleged |
| 62 | 8 | "Hit and Run" | Bill Roe | Vincent Angell | December 5, 2021 (2021-12-05) | 408 | 2 |
| Lopez asks Wesley to record everything when in contact with Elijah Stone, but he refuses due to client confidentiality and privilege. Nolan and Lopez arrive to talk to "sovereign citizen" Marvin Reynolds, but he shoots at them and escapes, becoming a wanted felon. Tim's sister Genny arrives in Los Angeles to sell their father's house. Harper and Aa |
| 63 | 9 | "Breakdown" | C. Chi-Yoon Chung | Alexi Hawley | December 12, 2021 (2021-12-12) | 409 | 2 |
| Tim and Lucy assist his sister, Genny, with refurbishing their childhood home. Tim discovers a gun in a wall, and he and Lucy open an investigation. The gun was suspected to have been used by Tim's father in a botched home invasion 25 years ago. His father had an affair with the neighbor's wife; she later confessed to having shot her husband in sel |
| 64 | 10 | "Heart Beat" | S. J. Main Muñoz | Fredrick Kotto | January 2, 2022 (2022-01-02) | 410 | 2 |
| Nolan learns of Bailey's marriage to Jason Wyler, who abused her psychologically and has just been released from prison early for good behavior. A small plane crash on the streets has the precinct staggered when no pilot is found. The plane's owner, billionaire Levi Lincoln, convicted of murdering his wife, turns up alive and having paid another ma |
| 65 | 11 | "End Game" | Tori Garrett | Terence Paul Winter | January 9, 2022 (2022-01-09) | 411 | 2 |
| Grey authorizes an investigation into Jason, and Nolan turns back to Oscar Hutchinson for further help along the way. Lucy and Tim investigate the murder of an 18 year old girl, Becca, who turns out to have been a friend of Tamara Colins. They learn that Becca had stolen a watch from a man she met on a social media app, and pawned it at a pawn shop |
| 66 | 12 | "The Knock" | Charissa Sanja- rernsuithikul | Zoe Cheng | January 23, 2022 (2022-01-23) | 412 | 2 |
| Nolan is elected as the station's union representative, aiming to accomplish changes, which is met with antagonism from the union president, Lt. Landon Briggs. Lucy and Tim discover a severed hand on the beach, which is identified to have belonged to Mark Klinke, who had managed to get himself to a hospital before dying. He worked for a biotech com |
| 67 | 13 | "Fight or Flight" | Lanre Olabisi | Brynn Malone | January 30, 2022 (2022-01-30) | 413 | 3 |
| Nolan and Lucy pursue a stolen police helicopter, which a teen, Leo, stole. Leo refuses to land until they fulfill three quests of his, the first of which includes a known drug house, where they arrest the occupants. The second includes a man connected to his stepfather, who was dealing drugs. Leo's third quest is that he wants them to arrest his s |
| 68 | 14 | "Long Shot" | Fernando Sariñana | Natalie Callaghan | February 27, 2022 (2022-02-27) | 414 | 3 |
| Skip Tracer Randy arrives at the station to meet Nolan and Harper about a bounty on a notorious Madam, Ivy Flynn, whom he sets out to capture. They roll out on a sting operation, where another bounty hunter, Alicia Kaufman, is about to apprehend Ivy before she escapes amid an argument. Alicia is revealed to be Randy's lover who wants to capture Ivy |
| 69 | 15 | "Hit List" | Robert Bella | Elizabeth Davis Beall | March 6, 2022 (2022-03-06) | 415 | 3 |
| Aaron's Plain-Clothes Day gets tough when he and Harper discover his mother's film crew following them. He later encounters the father of Patrick Hayes, the friend whom he was accused of having killed; Aaron is forced to arrest Patrick's father after he tries to punch him, but decides to let him go out of respect. As Grey is heading to court to tes |
| 70 | 16 | "Real Crime" | Rob Seidenglanz | Bill Rinier & Paula Puryear | March 13, 2022 (2022-03-13) | 416 | 3 |
| Aaron reality show crew interviews precinct officers about the crime investigation after the show's director, Morris Mackey, is murdered in Aaron's parents' home. Aaron himself is among the suspects. The documentary also brings up the murder of the second half of his father's rap duo, which is still unsolved. Patrick Hayes' father is also questione |
| 71 | 17 | "Coding" | Bill Roe | Nick Hurwitz & Sylvia Franklin | April 3, 2022 (2022-04-03) | 417 | 3 |
| Nolan is first on the scene of a car accident whose lone occupant suffered catastrophic injuries, but is still conscious. He talks with her as she dies. She's an organ donor, so he accompanies her body to the hospital. A teenager is first in line for the victim's heart. Harper is at the same hospital due to potential pregnancy complications. Lucy i |
| 72 | 18 | "Backstabbers" | Tori Garrett | Vincent Angell | April 10, 2022 (2022-04-10) | 418 | 3 |
| Nolan and Lucy join forces with Larry "Badger" Macer, who is now working for railway police, in investigating the robbery of a cargo train, where a vase was stolen from a freight car belonging to millionaire William Bloomfield. Together with Lopez and Harper, they learn that William's cellmate stole the vase, but is later found dead in his home. Wi |
| 73 | 19 | "Simone" | Liz Friedlander | Alexi Hawley & Terence Paul Winter | April 24, 2022 (2022-04-24) | 419 | 3 |
| Nolan and Lucy narrowly escape a bomb at a power station. The FBI is called in when it is suspected that the bomber belongs to a terrorist cell. When the FBI learns that the suspect, Zeke Freemont, has a connection to FBI trainee Simone Clark, they call her in to assist, but is soon dismissed. Nolan encourages her to stand up for herself. Lead agen |
| 74 | 20 | "Enervo" | Bill Roe | Alexi Hawley & Terence Paul Winter | May 1, 2022 (2022-05-01) | 420 | 4 |
| The LAPD and FBI race to stop bombs that have been scattered throughout the city on vans. Deducing that the targets are every freeway, Simone leads herself and Nolan in the direction of one of the trucks and stops it. The police manages to stop all but one of the vans from detonating. Garza and Grey approach the CIA in hope of help, but its leader, |
| 75 | 21 | "Mother's Day" | Lisa Demaine | Fredrick Kotto & Diana Mendez Boucher | May 8, 2022 (2022-05-08) | 421 | 3 |
| Grey expresses support for Nolan's desire to become a TO. They respond to a call at a film set, where a woman explains that another woman, Monica Ditmar, attempted to rob her. Tim and Lucy respond to a robbery, while Lopez and her mother-in-law are robbed. Grey and Nolan set up a boundary for Daniel Tran, a gang informant who is entering witness pr |
| 76 | 22 | "Day in the Hole" | Alexi Hawley | Alexi Hawley | May 15, 2022 (2022-05-15) | 422 | 3 |
| Nolan and Bailey travel to the border town of Frontera, where he is to spend his "day in the hole" with local trainee Gabrielle Navar. They arrest a man, Blair Darvill, who asks them to let him go before his gang gets suspicious, but Nolan refuses. Its leader arrives and tries to bribe Nolan, but when he refuses, the gang attacks the station-diner |