Murtaugh intercepts Riggs just as he is preparing to shoot and kill Tito Flores, the drug lord responsible for Miranda's death. He convinces Riggs to bring Tito back to the U.S. alive, in the trunk of Murtaugh's car. When they prepare to turn Tito over to U.S. authorities, however, they open the trunk and discover Tito has been shot in the head and killed.
Riggs and Murtaugh respond to the death of a plastic surgeon, drawing them into a case involving an illegal drug ring run out of a wellness clinic. The case has Riggs reconnecting with Agent Karen Palmer, who has been given desk work at the DEA ever since she leaked the Tito Flores file to Riggs. Karen, blind-sided by her greed to get out of the desk work, hijacks the investigation by interfering with Riggs job only to realize that she is not as efficient as she thinks she is. Begrudgingly, she
Riggs and Murtaugh, along with young detective Zach Bowman (Andrew Creer), investigate when the bodyguard of famous pop singer Shaye (Joanna Levesque) is murdered. The detectives uncover a secret relationship between Shaye and the bodyguard, along with an even bigger secret in Shaye's past. Meanwhile, Riggs and Palmer struggle to find normalcy in their relationship.
A lifelong con man (Adrian Pasdar) robs the passengers on a private plane at gunpoint while it is airborne, then leaps out with a parachute, taking a victim with him. Riggs and Murtaugh learn that the con man is dying and wanted one last haul to help his daughter after he's gone, but one stolen item (a briefcase full of uncut diamonds) has attracted a group of violent criminals. Meanwhile, Santos questions Avery's ability to lead, given his top detectives' penchant for danger.
Riggs and Murtaugh investigate a death that occurs moments before the victim's bet wins a horse race. The victim is Howard, a friend of Leo Getz. While it appears that Howard had a stroke, Getz is convinced it's murder, which Scorsese later proves to be true. Meanwhile, the city tows Riggs's trailer off the beach, bringing back painful childhood memories of being evicted.
Riggs helps his childhood friend Jake (Linds Edwards) get paroled from prison, but it soon becomes apparent that Jake is up to no good again. Noticing that Riggs gives Jake a lot of leeway, Murtaugh asks his partner if he owes his old pal a favor. Elsewhere, Murtaugh tries to find out which of his family members left a marijuana joint in a package of cookies, while Bailey gives Bowman a hard time just because he rejected her after she accidentally sent him a sext.
Riggs and Murtaugh work on the case of a dead surfer who just came into town from San Diego the day before. Bailey and Bowman help, and Bailey wonders why Bowman is treated like a hero in the beach town. Meanwhile, Murtaugh becomes suspicious of Trish's relationship with her charity ball co-chair "Scott", until he learns it is ex-NBA star Scottie Pippen. Also, Riggs deals with recurring nightmares.
Riggs and Murtaugh investigate a murder involving a couple and a New York mobster, Frank Truno. Scorsese reveals a movie script he has been writing, after he found out that the case revolves around the mafia. However, Murtaugh dislikes the way Scorsese accurately portrays him as one of the characters. Meanwhile, Riggs is taken aback when his childhood friend Molly (Kristen Gutoskie) suggests that they could have been romantically involved.
Jonah (Derek Richardson), a man with schizophrenia who believes that Elvis Presley is alive and controlling Hollywood's traffic, is running away from Riggs and Murtaugh after being suspected of murder. However, when he proves his theory, Riggs and Murtaugh must stop an organized heist conducted by men dressing as Presley. At the same time, Murtaugh tries to get his daughter into at an esteemed pre-school and Riggs gets scared when his relationship with Molly becomes romantic.
Murtaugh is ready for his family holiday in Hawaii until Diego, a young man he once helped, is murdered. Riggs and Murtaugh confront Grant Davenport (Martin Donovan), the president of an American upper class club where Diego was employed, who has ties to the Aryan fraternity. However, their confrontation causes the fraternity to ambush both of them. Murtaugh manages to subdue his attackers, but Riggs is only able to escape because of his father's assistance.
Riggs and Murtaugh take on a counterfeiting ring and are joined on the case by veteran Secret Service Agent Peterson (Ernie Hudson). A group of three teenagers inadvertently get involved when they witness a shooting and run off with the phony cash and plates. One of the teenagers named Ty (Nathan Davis Jr.) strikes a chord with Riggs after revealing he's homeless. Meanwhile, Riggs brings home a dog for Ben and Molly. Molly later finds the dog dead with its neck snapped. Sensing it's a message fr
Shortly after Gene Nakahara (C.S. Lee) meets with Trish and an uninvited Leo Getz to announce he is running against Councilman Sean O'Brien (Michael Reilly Burke) for Mayor of Los Angeles, Gene is killed when his car blows up. Riggs and Murtaugh learn of a private investigator named Serrano (Tim Kang) who works as a "fixer" for high-profile people and investigate that angle, while Trish and Leo work behind the scenes to reveal skeletons in O'Brien's closet. Riggs also learns that his late wife M
Dr. Cahill begins to question her abilities when two patients of hers die in separate incidents, until it is learned that they were briefly roommates in the same psych facility. Riggs and Murtaugh uncover corruption in the facility related to the medications both patients were taking. At the same time, Santos (Michelle Hurd) learns that Riggs had an anger incident caught on tape in which he destroyed the deputy mayor's car, and requests that Cahill sign an affidavit confirming that Riggs is stil
Detective Bailey's younger sister Jess (Alisha Wainwright) inadvertently gets caught up with a drug mob when she and her boyfriend use her waitress position at a high-end night club to steal a man's wallet. After the boyfriend is killed over the wallet's contents, Bailey walks a thin line between her obligation to the law and protecting her sister. Elsewhere, Murtaugh helps Riana spy on her boyfriend, whom she accuses of cheating, while Riggs loses his truck after a night of heavy drinking.
An elderly drifter named Ruthie (Swoosie Kurtz) is present at a jewelry store robbery, and becomes a key witness in the case. In the process, she and Riggs, who has recently vowed to stay sober, bond over their alcoholism. Meanwhile Murtaugh, fresh off being called "grandpa" at the playground while with his toddler, starts acting like Riggs and takes dangerous risks to prove he's not getting old. This gets him on Trish's bad side.
Riggs and Murtaugh track a group of criminals who stole numerous guns during a shoot-up at a police buy-back event. They locate and capture the group's leader, Booker (Sheaun McKinney), only to learn that he's working undercover for ATF. Avery learns from Booker's boss that Booker is a bit of a loose cannon, much like Riggs. Meanwhile, Riggs learns a little more about Ruthie's past and family situation, as Roger and Trish continue to fight at home.
With Riggs trying to get Murtaugh to make up with Trish and get out of his trailer, the two only make things worse when they ruin a public building implosion for Trish's latest project. An angry Trish tells the two that her client, grocery store magnate Henry Butler (Michael McGrady), now wants to bail on the project. Riggs convinces Butler to stay in town by inviting him to dinner. Riggs and Murtaugh discover that Butler is the man behind the murder, and Trish eventually also learns that her cl
About 16 years ago, Frankie Kelso (Jude Ciccolella), a contract killer, decided to show mercy on Murtaugh after the latter tried to arrest him at the scene of a hit. In the present, Murtaugh notices Kelso's signature at the scene of another killing. He captures Kelso, but the latter is able to get the upper hand and take Murtaugh hostage. Kelso insists that he is retired and that someone framed him for the recent crime. Riggs recognizes the name of one of Kelso's mob connections as someone who s
Leo is marrying Nina (Shakira Barrera), an ex-con, but she bails on the day of the wedding. Riggs and Murtaugh find her with a group of criminals trying to unload a bag of cocaine that "fell into" her purse at a high-stakes poker game run by a known mobster. At the same time, Riggs learns that Molly met with her ex-husband Jake, who is still a fugitive, and that Jake was at the same poker game. When Riggs catches up with Jake, the latter reveals he is planning to rob the safe at the poker game w
A break-in at a mansion turns deadly, and Roger and Trish are surprised to learn that Riana may be involved. It turns out that Phoebe, the sister of Riana's new boyfriend Jesse (Daniel DiVenere), is in possession of stolen diamonds from the heist and has become a target. Meanwhile, Riggs tries to be a good father figure for Ben, as he recalls the things he and Molly discussed in their teen years.
With Avery away at a conference, Murtaugh is appointed interim captain. His first case involves the kidnapping of Lisa Conlon, wife of a pharmaceutical magnate. Riggs is forced to get his father involved when it is revealed that the Aryan Fraternity of Texas (AFT) is behind the crime. In the process, Riggs learns that he has a 19-year-old half-brother, Garrett (Peter Coventry Smith), who is assisting the AFT. In exchange for his help, Riggs's father is let out of prison early. His comments to Ri
While Murtaugh visits Riggs, the latter's trailer is shot up by two men on motorcycles. The investigation leads back to Grant Davenport where Riggs and Murtaugh discover that Riggs' father is the former's bodyguard. Later on, a suspect tells Riggs that Murtaugh was the target of the shootout and Trish's senior partner in her workplace has been laundering money for the AFT. Riggs' father immediately kidnaps Trish. Riggs and Murtaugh release Riggs's half-brother, Garrett, to exchange him for Trish