The Crown’s Matt Smith and Assassination Nation’s Suki Waterhouse have signed up to star in Mary Harron’s forthcoming Charles Manson feature Charlie Says.

Smith, who has given up his throne as Prince Phillip in Netflix’s The Crown to make room for a later version of Phillip in the life of Queen Elizabeth, will play Manson. Hannah Murray (Game of Thrones, Detroit), Odessa Young (Assassination Nation) Marianne Rendon (Imposters, Gemini), Carla Gugino (Sin City, Watchmen), Kaylie Carter (Godless, Rings) and the Emmy-winning Merritt Wever (Godless, Nurse Jackie) also join the cast.

Based on Ed Sanders’ 1971 best-selling book The Family, as well as The Long Prison Journey of Leslie Van Houten, Charlie Says will focus on the three young women (Murray, Young and Rendon) who were sentenced to death following the infamous murder case of Manson (Smith). When the death penalty was lifted, their sentence became life imprisonment. One young graduate student, Karlene Faith (Wever), was sent in to teach them, and through her, the film will follow their transformations as they face the reality of their horrific crimes.

American Psycho director Mary Harron will direct from a screenplay by Guinevere Turner. Jeremy M. Rosen (Dog Eat Dog) and Kevin Shulman (I Am Fear) will produce.

Guinevere Turner’s script brings a fresh and unique perspective to the infamous story of the Manson murders and we have now found the perfect cast to bring it to life,” said director Harron.

Waterhouse can be seen in the Sundance hit Assassination Nation and has also recently joined the cast of Detective Pikachu alongside Ryan Reynolds.

Filming is due to start in L.A. in the Spring.