<Li> Seann William Scott (season 3) </Li> <Li> Jordana Brewster as Dr. Maureen Cahill, the police department's psychologist who treats Det . Riggs (and occasionally Det . Murtaugh). Although sometimes she is referred to as a psychiatrist and prescribes drugs (for example in "Better Living Through Chemistry"). The character is based on Dr. Stephanie Woods played by Mary Ellen Trainor in the film series . </Li> <Li> Keesha Sharp as Trish Murtaugh, Det . Murtaugh's loving wife and mother of his three children who works as a defense attorney . In the season one episode "As Good As It Getz", Trish quits her job after being passed over for managing partner at her law firm . She was originally played by Darlene Love in the film series . </Li> <Li> Kevin Rahm as Captain Brooks Avery (seasons 1--2), the Commanding Officer of Robbery - Homicide Division . Before his promotion, Capt . Avery was partners with Det . Murtaugh . In "Lawmen", it is revealed that years ago he and a Los Angeles County Sheriff's Department deputy (Malcolm - Jamal Warner) planted evidence to convict a murderer after previous evidence was excluded from trial; he was prepared to resign over the incident when it came to light, but Murtaugh convinced him to stay because if his impropriety was revealed it would mean that all of Avery's cases (many of which he worked with Murtaugh) would be reviewed if not overturned entirely . In "Family Ties", he decides to retire from the force in order to run for office . The character is based on Captain Ed Murphy played by Steve Kahan in the film series . </Li>

Who plays murtaugh's wife on lethal weapon