This is so true. Probably like most people here, I read a lot of true crime and I have read some books where you can just see how hard the author is trying to sell their theory. I just finished a book on the Boston Strangler, with the take that DeSalvo was not the strangler. I have believed for years that he was not, but the recent DNA evidence, along with reading this book wich was supposed to convince the reader that he, absoloutely was not the Strangler, has actually convinced me that he was.
That probably makes no sense to anyone but me, but sometimes I just find authors try so hard to make their cases, to me it is so forced it has the opposite effect.
Not always, there are many books I have read (Fatal Vision and Small Sacrifices come instantly to mind) that have absolutely, positively convinced me of the author's theory. But in those cases there is always so much evidence, both circumstantal and forensic, that I see no other conclusion.
When it is just a bunch of the author's conspiracy theory stuff, I come away not only disappointed, but often convinced of exactly what the author did not want to convince me of.