The lethal weapon the tv series cast is easiest to follow if you split the show into two eras: the original Murtaugh-and-Riggs seasons, then the Season 3 reset with Wesley Cole. Damon Wayans stayed at the center as Roger Murtaugh, while Clayne Crawford defined the first two seasons as Martin Riggs and Seann William Scott took over the partner role in the final season.
Who is in the main cast of Lethal Weapon?
The main cast mixes three things: Murtaugh's police partnership, his family life, and the LAPD characters who keep the cases moving. If you are starting the show from the beginning, the key names to know first are Damon Wayans, Clayne Crawford, Keesha Sharp, Jordana Brewster, and Kevin Rahm. If you are jumping into Season 3, Seann William Scott becomes just as important.
Damon Wayans as Roger Murtaugh
Damon Wayans plays Roger Murtaugh, the experienced LAPD detective who anchors the series. Murtaugh is not just the "responsible partner"; he is also a husband and father whose home life shapes how he reacts to danger.
That matters because the show often works best when Roger is caught between two worlds: chaotic police work and the ordinary family life he wants to protect. Wayans gives the role enough humor and frustration to keep Murtaugh from feeling like a plain authority figure.
Clayne Crawford as Martin Riggs
Clayne Crawford plays Martin Riggs in the first two seasons. Riggs is grieving, reckless, sharp, and unpredictable, which gives the early episodes their most volatile energy.
If you are watching for the original buddy-cop chemistry, this is the version of the show people usually mean. Riggs pushes Murtaugh into riskier situations, but the partnership gradually becomes more personal than either character expects.
Seann William Scott as Wesley Cole
Seann William Scott joins as Wesley Cole in Season 3 and becomes Murtaugh's new partner. Cole is a former CIA operative, so the show gives him action credibility right away, but he is not written as a copy of Riggs.
His arrival changes the viewing experience. Fans who liked the darker Riggs storyline may feel the shift immediately, while viewers who prefer a cleaner reset may find Cole easier to settle into.
Keesha Sharp as Trish Murtaugh
Keesha Sharp plays Trish Murtaugh, Roger's wife and one of the strongest parts of the family side of the series. Trish is smart, direct, and often the person who cuts through Roger's excuses when police work spills into home life.
She helps keep the stakes personal. When Roger takes risks, the show has already shown the people who have to live with the consequences.
Jordana Brewster as Maureen Cahill
Jordana Brewster plays Dr. Maureen Cahill, the police psychologist most closely tied to Riggs's emotional story. Her scenes give the first two seasons room to deal with grief and trauma instead of treating Riggs only as a reckless action character.
Kevin Rahm as Brooks Avery
Kevin Rahm plays Captain Brooks Avery, the boss who has to manage the fallout from Murtaugh and his partners. Avery brings structure to the precinct scenes, but he also adds dry comedy because he is often the person left cleaning up the mess.
Chandler Kinney as Riana Murtaugh
Chandler Kinney plays Riana Murtaugh, Roger and Trish's daughter. Her role helps show that Roger's decisions affect more than his job, especially when family arguments, teenage independence, and police danger overlap.
For viewers who care more about the character side than the case-of-the-week format, the Murtaugh family scenes are worth paying attention to because they explain why Roger is cautious in a way Riggs often is not.
Dante Brown as Roger Murtaugh Jr.
Dante Brown plays Roger Murtaugh Jr., another part of the family foundation around Roger. The role is quieter than the detective partnership, but it helps make Murtaugh's home life feel like a real part of the series rather than a quick break between action scenes.
Who joined the cast in Season 3?
Season 3 is the major cast reset. The show does not simply add a new detective; it builds a new circle around Wesley Cole so the final season has its own family ties, work conflicts, and backstory.
Seann William Scott as Wesley Cole
Seann William Scott is the biggest Season 3 addition because Wesley Cole replaces Riggs as Murtaugh's partner. The character brings a CIA background, field skills, and a more easygoing style than the earlier lead dynamic.
- Riggs-era viewer: expect a different tone, not a direct continuation of the same chemistry.
- New Season 3 viewer: Cole is written with enough personal baggage to work as a co-lead, even if you know little about the earlier seasons.
Maggie Lawson as Natalie Flynn
Maggie Lawson plays Natalie Flynn, a key figure in Cole's personal life. She helps the season show what Cole is trying to repair or protect when he is away from the precinct.
Natalie's role is useful because Cole could otherwise feel like a generic "former operative" character. Through her, the show gives him a more ordinary emotional pressure point.
Shay Rudolph as Maya Flynn
Shay Rudolph plays Maya Flynn, who adds another family connection to Cole's Season 3 story. Her presence makes Cole's choices feel less abstract, especially when the show contrasts his dangerous past with the life he is trying to have now.
Mykelti Williamson as Tom Barnes
Mykelti Williamson plays Tom Barnes, a character connected to Cole's CIA history. Barnes gives the season a way to bring Cole's past into the present without relying only on exposition.
When Barnes appears, the show can lean into a more tactical, history-driven kind of conflict. That is one of the clearer differences between the Cole era and the earlier Riggs era.
Paola Lázaro as Luisa Gutierrez
Paola Lázaro appears as Luisa Gutierrez, part of the refreshed Season 3 ensemble. Her role is not the central replacement story, but she helps broaden the later cast at a point when the show needed new voices around Murtaugh and Cole.
How did the Lethal Weapon cast change?
The cast changed most sharply between Season 2 and Season 3. Clayne Crawford left, Martin Riggs was written out, and Seann William Scott joined as Wesley Cole. That means the show keeps Roger Murtaugh as the constant but changes the partnership that originally defined it.
| Part of the show | Seasons 1-2 | Season 3 |
|---|---|---|
| Central partnership | Murtaugh and Riggs | Murtaugh and Cole |
| Main emotional weight | Riggs's grief and instability | Cole's family ties and past |
| Best starting point | For the original chemistry | For the post-Riggs reset |
Clayne Crawford left after Season 2
Clayne Crawford left after Season 2, which created the show's biggest cast break. His exit was widely reported in connection with on-set conduct and production issues, and because he played Martin Riggs, the change affected the whole structure of the series.
Martin Riggs was killed off
Martin Riggs was killed off after Crawford's departure, giving the story a firm break instead of leaving the character waiting off-screen. It allowed Season 3 to move forward, but it also removed the emotional engine behind much of the first two seasons.
Wesley Cole replaced Riggs as Murtaugh's partner
Wesley Cole replaces Riggs as Roger Murtaugh's partner in Season 3. Seann William Scott plays him as capable and funny, but with a softer edge than Riggs.
Season 3 added Cole's family and CIA past
Season 3 adds Cole's family connections and CIA background so the new partner does not feel temporary. Natalie, Maya, Barnes, and other additions give Cole personal stakes and explain why his approach to danger differs from both Murtaugh and Riggs.
Conclusion
The cast works best when you view the series by era: Seasons 1 and 2 belong to the Murtaugh-Riggs dynamic, while Season 3 is the Murtaugh-Cole reset. If you want the strongest original chemistry, start at the beginning; if you mainly want to understand the later cast change, Season 3 shows how the series tried to rebuild around a new partner without replacing Roger Murtaugh as its anchor.