I also read his other book, “Murder in Little Egypt”. It’s about a doctor from southern Illinois who killed two of his children for the life insurance money, and committed a LOT of other crimes too. I lived in the area for a while, and some people still nearly worship the guy, 30 years later. 
Some others that immediately come to mind include:
Suffer The Little Children (a man who killed relatives and abused many people terribly)
Green River, Running Red (Ann Rule book about Gary Ridgway’s victims; all of them had heartbreaking lives)
The Pied Piper of Tucson (serial killer from the mid 1960s; the book was written not long afterwards)
Gerold Frank’s “The Boston Strangler”
The Good Nurse (current bestseller; its subject, Charles Cullen, was recently profiled on “60 Minutes”)
Blind Eye, about medical serial killer Michael Swango; I used to live in a city where he practiced, and heard plenty of stories about him
Too Young To Kill, about a group of teenagers who killed someone who thought she was their friend
and plenty of others, too.
I actually prefer true crime books about women criminals, because people tend not to suspect them, and honestly, women who are wired this way are WAY more dangerous than men.
p.s. The new book about Charles Manson, the one with the bright yellow cover and Manson as a smiling adolescent, is quite interesting too. 99% of the people who met him throughout his life hated him instantly; the other 1% worshipped him and this was how he managed to have his little mini-cult.