Officer John Nolan and Officer Nyla Harper are assigned to a community policing center to help rebuild their station’s reputation in the community. Nolan is determined to make a positive impact but Nyla has her doubts.

Officer John Nolan's mom makes an unannounced visit that complicates his life, and Sergeant Grey considers retiring.

Officer Nolan’s decision to return to school in order to become a training officer is proving to be much harder than he expected. Meanwhile, Officer Chen considers going into undercover work after getting a taste of the job when Harper’s former colleague needs help.

When professor Fiona Ryan’s car window is smashed following a series of mysterious notes, Nolan volunteers to guard her house overnight. Lucy notices that Tim is being much nicer to his new boot than he was with her and she does not like it.

After rushing his son, Henry, to the hospital following his collapse, Nolan is reunited with his ex-wife, Sarah, and they must come together to help their son. Meanwhile, Detective Lopez discovers “La Fiera” is in the same hospital and wants to find out exactly why.

Officers Nolan and Bradford hope they can de-escalate a drug war before any innocent lives are lost. Meanwhile, Officer Harper hopes she can get Officer Chen ready to go undercover.

Officer Nolan mildly injures himself while chasing down a shoplifter and the local DA wants to charge the suspect with assault despite Nolan's wishes. Meanwhile, Lucy goes undercover, Lopez' wedding venue is seized by the FBI and Nolan meets his new neighbor.

Officer Nolan and Officer Chen’s run-in with an infamous thief tips them off to a potentially big heist surrounding the Getty’s big gala event. Meanwhile, Nolan works up the courage to ask Bailey out on a date.

When a new designer drug hits LA streets, it turns users into “zombies,” and Officer Nolan and the team have a Halloween they won’t soon forget. Back at home, Lucy questions whether her apartment building might be haunted.

Desperate to break free from his connection to Elijah, Wesley tries to plant a listening device in his office to incriminate him; Officer Bradford and his sister, Genny, learn an unsettling truth about their father.

The team must rely on a criminal for his expertise to help take down an even bigger threat. Meanwhile, Officers Chen and Bradford investigate the murder of an unhoused teenager who used to be friends with Tamara.

Officer Nolan and Detective Harper help Skip Tracer Randy on his first bounty hunter case. Meanwhile, Officer Chen and Sergeant Bradford are on the hunt for a perpetrator on a citywide crime spree.

Officer John Nolan and the team feel they must negotiate with a distraught man who is holding a hospital hostage to ensure his wife receives a lifesaving surgery.

Officer John Nolan is forced to spend a week in solitary confinement in a quiet border town with a young local officer who is in need of some training. Meanwhile, Sergeant Bradford and Officer Chen discover that looks are deceiving and go undercover together in a possible drug trafficking case.

Officer John Nolan is once again face-to-face with serial killer Rosalind, and she wants him to know she's not done with him yet. Meanwhile, officers Bradford and Chen work undercover with Detective Lopez and the Las Vegas Police Department to arrest leaders of a major criminal enterprise.

Officer John Nolan is assigned his first rookie, Officer Celina Juarez, whose unconventional approach to police work poses a unique challenge for him.

Nolan and Celina must stand guard at a hospital after a dangerous prisoner needs surgery. Aaron, Lopez and Harper look into a string of robberies. Tim and Lucy consider how their secret relationship will affect their work. Lopez gets unexpected news.

Officer John Nolan and Bailey are on the hunt for a mystery gunman after a shooting hits a little too close to home. Meanwhile, Aaron struggles to live within his means and joins Lucy to help Tamara when the mother of a child she babysits goes missing. Elsewhere, Wesley suspects that a judge is taking bribes after he excludes valuable eyewitness testimony from a case.

Officer Tim Bradford’s ex-wife returns and asks the team to help her save someone from her undercover past. Isabel’s return also creates additional pressure in Lucy and Tim’s relationship as they assist in the search.

When a toddler is found at the scene of a crime, John and Bailey must decide whether to let the child go to a shelter for the night or care for her themselves. Meanwhile, when someone from his past returns, Tim disappears and leaves Lucy in the dark.

Following their time as foster parents, Bailey has decided she wants to have a baby and forces John to reconsider their decision to not have children. Meanwhile, John and Celina discover a prison escapee whom they fear is out for revenge and race to find her before it is too late.

When two teenagers go missing, it is up to the entire team to find the girls and uncover the truth about their disappearance. Meanwhile, Lopez and Harper are on a different kind of investigation – the search for the perfect nanny.