Derek Richardson
“Anger Management” alum Derek Richardson will guest star as a conspiracy theorist in Season 2, episode 9 of “Lethal Weapon.” Pictured: Richardson arrives at the Hollywood FX Summer Comedies Party in Los Angeles on June 26, 2012. Reuters/Gus Ruelas

Derek Richardson has landed a guest-starring role on Fox’s “Lethal Weapon.”

Richardson will appear in next week’s Season 2, episode 9 of the buddy cop series. According to the synopsis for the installment, Richardson will play a conspiracy theorist named Jonah.

In the trailer for the installment, Jonah is arrested and is brought into questioning. “Something crazy is going on right here in Los Angeles,” Jonah tells Riggs (Clayne Crawford) in the interrogation room.

When Riggs reveals to Jonah that he speaks crazy, the arrestee starts to open up and claims that Elvis Presley is controlling the traffic. After learning what Jonah said to Riggs, Murtaugh (Damon Wayans) concludes that Jonah is “insane.” But Riggs doesn’t think the same way.

Later in the promo clip, Murtaugh finds out that Jonah is telling the truth, as the detective spots a man dressed as the late Elvis Presley who appears to be controlling the traffic lights using a remote control-like device.

Murtaugh immediately calls Riggs to tell him what he just found out: “Elvis has left the building … back from the dead and strapped.” Although Riggs appear to be on a date with Molly (Kristen Gutoskie), he is more than willing to respond to the call of duty. In fact, Riggs — who seems to be showing Molly around Los Angeles when Murtaugh calls him up — casually jumps off from the second level of the open top bus they are riding just to help his partner catch the Elvis Presley copycat.

Richardson is best known for his role as Nolan Johnson on the FX sitcom “Anger Management.” The 41-year-old actor is also known for his roles as Josh Brooks in the “Hostel” film series and Harry Dunne in “Dumb and Dumberer: When Harry Met Lloyd.”

Aside from Richardson and Molly, Fiona Gubelmann and Alexie Gilmore also guest star in the episode as Andi and Dr. Weir, respectively.

Elsewhere in the episode, Murtaugh and Trish (Keesha Sharp) attempt to get their youngest child Harper into a fancy pre-school.

“Lethal Weapon” Season 2, episode 9, titled “Fools Rush In,” airs on Tuesday, Dec. 5 at 8 p.m. EST on Fox.