Rachel Brosnahan and Christopher O’Shea have joined the Boston Marathon bombing movie “Patriots Day” opposite Mark Wahlberg, John Goodman, J.K. Simmons, Kevin Bacon and Michelle Monaghan.

The film is directed by Peter Berg  and produced by Wahlberg, Scott Stuber, Hutch Parker, Dylan Clark, Stephen Levinson, Dorothy Aufiero and Michael Radutzky. Shooting has started in Boston.

Brosnahan will play Jessica Kensky and O’Shea will portray Patrick Downes. Newlyweds Kensky and Downes were at the finish line to cheer on marathon runners the day of the bombings. Both survived but were seriously injured.

“The survivors are the heart of this story and Rachel and Christopher are bringing their immense talents and their respect for Jessica and Patrick’s extraordinary courage to the film,” commented Berg.

Brosnahan starred in Netflix’s “House of Cards” and O’Shea appeared in the TV movie “Point of Honor.”

She is represented by Innovative Artists, Carole Dibo Talent Mangement and Shreck Rose Dapello & Adams. O’Shea is repped by Innovative Artists, Haven Entertainment and Todd Rubenstein.

The film is co-financed by CBS Films and Lionsgate, with the former handling production and marketing, and the latter handling distribution.

“In Treatment” star Alex Wolff and Themo Melikidze recently joined the cast as Dzhokhar and Tamerlan Tsarnaev, the brothers responsible for the Boston Marathon bombing. The film is based on accounts from the 2013 bombing, which killed three and injured 264 others, and the ensuing search for the Tsarnaev brothers.

The film co-stars Jimmy O. Yang, Michael Beach, Vincent Curatola and James Colby. It will open in limited release on Dec. 21.

Wahlberg will portray a Boston Police Department officer who was central to the investigation and manhunt. Curatola will play longtime Boston Mayor Thomas Menino. Bacon is FBI agent Richard DesLauriers; Colby is Billy Evans — the superintendent in charge of the Boston Police Department; and Goodman is police commissioner Ed Davis.