Murder C.O.D.

Alex Brandt (Devane) is a serial killer with a novel way of making money off his mental disability: find someone who has bitter disagreements with someone else who has money and off him. Then bill the rival 100 grand as a fee for services rendered backed up with the threat of framing them for the murder if they say no. Eventually a cop figures out what he's up to and gets billed for Brandt's services to hush him up.