The movie Copycat follows psychiatrist Helen Hudson who studies serial killers. After an attack by serial killer Daryll Lee Cullum, Helen suffers from agoraphobia. While in prison, Daryll encourages another killer, William McNamara, to target Helen by copying the methods of other famous serial killers. When three similar murders occur, Helen contacts the police but they dismiss her tip until officer M.J. Monaham decides to involve Helen in the investigation.