She is portrayed by Jordana Brewster.
Cahill has a history of being known for helping police officers in the LAPD, through the most traumatic moments in their lives.
Cahill takes her job as a psychologist very seriously, and only wants to help police officers through the most traumatic events in their lives as much as possible, especially Martin Riggs; under the impression from Roger Murtaugh that Riggs may be suicidal and dangerous, as she's often seen with Riggs when she talks with him about the events in his life. She's shown to be very thoughtful and very concerning as she wants to help Riggs. She's often in a meeting with Murtaugh at times, who she often helps, as well.
To view the Maureen Cahill gallery, click here.