The killer is Joe Smith, played by guest star Eddie Cibrian .
Smith is a particularly manipulative serial killer who uses his young son to lure women into a false sense of security before abducting and murdering them. [S3E2] In Birth and Death
Despite these internal crises, the remaining members—including Derek Morgan, JJ, Reid, and Garcia—must investigate a serial killer in Milwaukee. Key Plot Details The killer is Joe Smith, played by guest star Eddie Cibrian
has gone missing (effectively leaving the team). Aaron Hotchner has been suspended. Emily Prentiss has resigned (though she later returns). The killer is Joe Smith