“Anonymous Killers” (** out of four) was a mildly diverting horror melodrama about four professional killers and one professor (Patrick Caberty, Natassia Halabi, Kevin Glikkman, Gabriela Lopez, and Dominic Pace) who are captured by a demented maniac (Andrew Bongiorno) and held in chains for which the reason for this remains a secret. Relatively well-made and well-paced but many filmgoers may note after a while this is a little overly similar to “Saw” and also “Rashomon.” OK for what it is.