The SWAT team faces difficult reminders of a past school shooting when they receive a warning that a copycat plans to re-enact the crime. As the team races to stop the new threat, they flash back to the day of the tense first mission.

After the shocking shooting of a member of 20-Squad, Hondo and the team launch a citywide manhunt for the robbery crew responsible. Meanwhile, Deacon's plans for his future hit a snag, and Powell and Alfaro clash over a tricky issue.

SWAT faces their deadliest adversary yet when a violent cell of extremists looks to extract vengeance by blowing up half of Los Angeles, potentially killing thousands.

The abduction of Luca and Street’s neighbor sends the SWAT team in pursuit of a home invasion crew targeting domestic workers to gain entry into upscale homes. Also, the SWAT division prepares to help Mumford mark a major career milestone.

When control of a university chemistry lab is seized, the team races to thwart a devastating terror attack.

The team works with the DEA and their iron-jawed leader, Mack Boyle, to stop a ruthless cartel boss waging war on the streets of Los Angeles as he exacts revenge on those who killed his son.

The SWAT team faces off with a family of doomsday preppers barricaded inside their fortress of a home, and Deacon finds himself at the center of the storm. Also, Tan clashes with a reporter covering the situation and Powell grapples with meeting the child she gave up for adoption 18 years ago.

As 20-Squad scrambles to track down a cold-blooded sniper terrorizing Los Angeles, Hondo discovers a link to his own South L.A. neighborhood that brings a personal twist to the hunt for the deadly shooter. Meanwhile, Tan finds himself questioning his leadership abilities while Powell and Alfaro compete in a classic game of SWAT tag.

Hondo and Lina go undercover to infiltrate and take back a cruise ship that’s under siege by drug smugglers who will execute passengers if they detect police on board. Street enters the SWAT Training Academy and finds the competition fiercer than he expected.

The SWAT team sets out to recover dozens of DNA evidence kits stolen from an LAPD crime lab and bring in the crew responsible, after a close friend of Hicks is harmed during the theft. Financial strain at home makes it difficult for Deacon to focus on his role as leader of the SWAT division’s annual holiday toy drive.

The SWAT team finds itself under internal investigation after a civilian is killed as they attempted to bring in the city’s most wanted criminal. As the mission details are revealed, the force’s internal affairs team calls Hondo’s leadership into question.

Hondo and the SWAT team rally to support Street when he puts his life on the line to help his foster brother Nate break away from a drug ring.

When Deacon enlists Chris’ help on an off-duty private security detail, they struggle to survive when they’re attacked by a drug cartel looking to kidnap their wealthy VIP client, on the new day and time.

When a plane carrying Street and the dangerous prisoner he's transporting is hijacked, the team races to save the innocent passengers onboard -- and one of their own; Hondo takes a big step in his relationship with Nichelle.

While training with Long Beach SWAT, Street discovers a biker club has stolen a cache of armor-piercing bullets and brings 20-Squad into the hunt for the gang before they can pull off a daring and deadly heist. As Hondo struggles with changes at work, Nichelle finds herself at odds with her former colleague Bruce.

Tan finds himself on a one-man mission to save his new love interest and her journalist co-workers when mercenaries take over a black-tie correspondents' dinner. After the group escapes, it's up to SWAT to track down the well-trained gunmen.

As the SWAT team goes inside a prison riot to rescue civilian hostages, Hondo suspects the inmates have an ulterior motive behind the uprising. Also, when Deacon’s wife, Annie, stops by headquarters to celebrate Deacon’s 10th anniversary with the SWAT division, her visit takes an unexpected turn.

The SWAT team goes in pursuit again of the militant group The Emancipators, when the criminals hold a live stream kangaroo court to publicly execute city politicians. Also, Hondo fights to lift Darryl’s spirits; Deacon feels unworthy as he prepares to receive one of the LAPD’s highest honors; and Street catches a break in the search for his missing parolee mother.

When bodycam footage left at a local news station seems to show Hondo shooting two police officers, he is forced to go on the run while the team works to clear his name.

When a home invasion turns deadly, the team embarks on a race to track down priceless antique artifacts before any more lives are lost; Leroy enlists Hondo's help after an overdose hits close to home.

When a misconduct complaint filed against Hondo gets him taken off active duty, Deacon steps up to lead the team in finding a robbery crew that is hitting marijuana dispensaries. Also, when Tan notices a similarity between the current robberies and a case from his time with Hollywood LAPD, he asks for help from an informant with whom he has a complicated history.

The SWAT team hunts for a band of criminals re-enacting the crimes of the infamous Symbionese Liberation Army. Seeking expertise on the original crime spree in the 1970s, Luca and his father review the files of Luca’s late grandfather who worked for SWAT during the era of the original crimes. Hondo experiences discrimination from a fellow officer during a SWAT training seminar for local law enforcement in Arizona.

When a female robbery crew "honeytraps" and kills several rich VIPs, Hondo and 20-Squad are called in to assist FBI Agent Jackie Vasquez in capturing the dangerous fugitives before the death toll rises. Commander Hicks is shocked when his new love, Maggie, abruptly ends their relationship without rhyme or reason. With help from Deacon and Dr. Wendy, Hicks makes an important decision about his romantic future.

When a series of home invasions are committed by SWAT imposters in an upscale neighborhood, Hondo and the team suspect the burglarized families are all hiding something. Also, when Deacon and Luca are assigned to protect a visiting professional hockey player who is receiving death threats, his penchant for trouble becomes a complication. [also shown as S1:E6]

When the SWAT team is called in to work on their day off to end a hostage situation, they discover one of the captives is a wanted felon. When Hondo saves his sister after she's been roofied at a nightclub, he uses his day off to hunt a serial rapist.