The cast of the CBS drama series “NCIS: Los Angeles” has added a series regular who will be introduced in the season nine premiere. CBS announced that Nia Long will play the team’s new executive assistant director, Shay Mosely.

The season premiere is set for Sunday, Oct. 1.

“As a former Secret Service agent now working for the Naval Criminal Investigative Service, Mosely is an experienced Washington insider who brings an east coast style and demeanor to the west coast team,” CBS says in its announcement.

Adds executive producer R. Scott Gemmill: “The character was created specifically for Nia to capitalize on her strengths and personality, and we are excited about the new opportunities and dynamics she brings to the show. We couldn’t be happier to have her join our family.”

Long’s film credits include “Boyz N the Hood,” “Friday,” “Soul Food,” “Love Jones,” “The Best Man,” “Boiler Room,” “Big Momma’s House,” “Alfie,” “Are We There Yet?,” “Big Momma’s House 2,” “The Best Man Holiday” and “Keanu.” She will also be seen in the indie film “Lemon,” from director Janicza Bravo, which premiered at Sundance and will be released nationwide Aug. 18.

“Long is the ambassador for the United Nations Foundation’s Nothing But Nets program, a global, grassroots campaign to save lives by preventing malaria, a leading killer of children in Africa,” CBS notes. “This month, she is traveling to Tanzania for the campaign, to visit the world’s largest refugee camp where she will meet with refugee families and distribute insecticide-treated mosquito nets that help keep families safe from the disease.”