The Conspirator: Mary Surratt and the Plot to Kill Lincoln: Mary Surratt was the only woman convicted in Lincolns assassination, the first female to be executed by the U.S. government and now the basis for Robert Redfords The Conspirator. Just days before the feature film hits theaters, NGC presents a complementary documentary on her role in the 16th presidents death. The Plot to Kill Lincoln: The Conspirator weaves together excerpts from the movie with historical records and expert interviews to tell the dramatic story.