scamdrel
A low life criminal entrepreneur who targets people to run his treacherous business practices upon. Different than a scammer, who is more akin to a fisherman casting a huge net, a scamdrel uses a big hook, and chooses his prey based upon value and vulnerability. His prize - their money; either directly or by selling faulty or flawed goods.
My neighbor, a lonely spinster, was victimized by a dirty rotten scamdrel, who wooed her to get at her bank account.