What Happens Next With Cuchet and Her Son?

A French journalist thinks that Cuchet began to blackmail on re because she realized what he was doing. This is an excellent motive for murder when you are trying to blackmail someone who you don't know has the ability to be violent. And this journalist thinks that's what happened to Cuchet and her son. He got fed up when he was being blackmailed and he killed them, then we start on many, many murders after that.