Veteran buttoned-down LAPD detective Murtaugh is partnered with slightly unhinged, former Navy SEAL Riggs. The odd couple embark on their first homicide investigation as partners, involving a young woman known to Murtaugh with ties to a drug and prostitution ring.

Responding to a noise complaint at a party at heavyweight boxer Ronald Dawson's Hollywood Hills home, Riggs and Murtaugh are drawn into a major case involving illegal gun runners with advanced military technology.

Riggs and Murtaugh follow a violent case involving a drug cartel, theft, killings, and Murtaugh's old T.O., Ned Brower. As the case unfolds, it turns out Ned's more involved than just driving the cash, which leaves Murtaugh with an inevitably dangerous decision to make.

A string of burglaries hits close to home for Murtaugh when one occurs in his own neighbourhood, and it gets just as personal for Riggs when another break-in ends in a casualty.

Murtaugh delves deep into the psyche of a former Navy SEAL who is wanted for criminal activity, and draws parallels between him and his partner Riggs. Riggs' connection to the suspect threatens to interfere with the case, but it also forces him to open up to Murtaugh.

When Riggs and Murtaugh investigate a high-profile case surrounding the murder of a young model, they uncover a vicious secret behind the locked mansion gates of one of LA's wealthiest families. Riggs gets surprised when an old friend of his wife has ties to the case.

As Riggs and Murtaugh examine the murder of one of L.A.'s fashion expeditors, the trail of evidence leads them to an ongoing and exceptionally dangerous underground investigation led by the DEA.

When a million dollar casino heist takes a deadly turn, Riggs befriends the only credible witness, an 8-year-old boy, and takes him into his care. On the flip side, Murtaugh pulls some dangerous stunts in an attempt to prove to everyone that he can be a motorcycle guy.

The whole precinct's holiday celebrations are cut short when they're called to examine a ruthless homicide linked to Eddie Flores, the deranged nephew of a notable drug lord who has a previous history with Riggs.

After investigating the murder of a millennial "designer drug" dealer, Riggs and Murtaugh find themselves in a violent turf war between a new generation of drug dealers and a Koreatown gang.

Murtaugh and Riggs are pitted against the LA Sheriffs Department when the killing of a Texas Ranger leads them to believe a possible misuse of power is at play. The case becomes even more complicated when a dark secret is dug up from Captain Avery's past.

When a car containing massive amounts of cocaine is stolen from an impound lot, Riggs and Murtaugh become embroiled in a notorious car theft ring, and the lead defence attorney on the case is none other than the terrifyingly brilliant Trish Murtaugh.

Riggs and Murtaugh investigate a series of violent crimes with one thing in common - the victims are all members of the same church. While investigating the case, Riggs faces a dilemma of his own when the one-year anniversary of Miranda's death sends him to a new low.

A brutal car crash reveals that Cahill is the target of a murderous stalker, causing Riggs and Murtaugh to start asking her questions for a change. Meanwhile, after finding Murtaugh's file in Cahill's office, Riggs becomes obsessed with finding out about his past.

Riggs and Murtaugh are forced to work with DEA agent Karen Palmer again, to protect Leo Getz, an ambulance-chasing attorney linked to the Cartel. As the three delve further into the case, they begin to realise that Leo may not be the only one with a target on his back.

A murder involving a high school football phenomenon draws Riggs and Murtaugh into the lucrative and corrupt world of college recruiting. Murtaugh considers a big change in his professional life and Riggs contemplates an even bigger shift in his personal life.

Riggs and Murtaugh team up again with DEA Agent Karen Palmer, and together they gain inside knowledge of dangerous new cartel operations. As Riggs' attachment to Palmer deepens, so do his impulsive actions, further worrying Captain Avery and Delgado.

Riggs makes a shocking discovery about Miranda's death that leads him back to the cartel in a frantic search for answers. His wild desperation leaves Murtaugh torn between his commitment to his partner and his commitment to his family.