H.H. Holmes used to be one of my "favorite" serial killers until I read this book which changed pretty much everything I thought I knew about him
This book really changed my opinion of Holmes. Turns out he didn't kill nearly as many people as he's given credit for.
Except it was never a "murder hotel" and he killed way less people than he's given credit for Source
Actually it turns out a lot of the sources Larson used were false/exaggerated Source
This book is a good one