This is absolutely fascinating. I had never heard of either Petiot or the fact that there had been a serial killer in Nazi-occupied France. I'm not even certain I'd heard of the French Gestapo. Unfortunately, I have to agree that Petiot was not given a fair trial - frankly I think the trial was ridiculous. Of course, the unfairness was all in his favour, and not the prosecution's (or, more importantly, history's). There are so many questions that will never be answered. And some that I think the author should have answered - the story at the end, for example, (view spoiler)[the man claims to have survived the gassing and so on. How? It's all very well to say that it happened. And it's certainly interesting that an anonymous member of the French Gestapo claimed that that was how it was done. But it doesn't answer the question of how the man survived to tell the tale (hide spoiler)]. Either way, this has brought to light a number of interesting things that I will look into further.