Michael Beach has been elected to Patriots Day, the CBS Films and Lionsgate pic about the events surrounding the Boston Marathon bombing. The Third Watch alum — who is recurring as Pike on the current third season of The 100 — will play Deval Patrick, the governor of Massachusetts when terrorists struck the annual event in 2013.

As the manhunt unfolded, Patrick gave the order to shut down the region’s transportation system and asked Boston’s 1 million-plus residents to shelter in place.

The pic also features Kevin Bacon, John Goodman, J.K. Simmons, Jimmy O. Yang, Vince Curatola and James Colby. Bridge of Spies Oscar nominee Matt Charman penned the script. Scott Stuber, Wahlberg, Hutch Parker, Dylan Clark, Stephen Levinson, Dorothy Aufiero and Michael Radutzky are producing. CBS Films is handling production and advertising for the film, which Lionsgate will open December 21.

Beach starred for five seasons on Third Watch and recurred on Sons of Anarchy as Grim Bastards president T.O. Cross. He also just landed a role in Fox’s drama pilot Pitch, playing the father of Ginny (Kylie Bunbury), the first woman to play in the major leagues. His other recent credits include Crisis and arcs on Secrets and Lies, and The Game. He is repped by Global Artists Agents.