You can also try to read "A MIRROR ABOVE THE ABYSS" by Oleg Lurye. The author tells about different horrific events of our history. However, there are some fictional characters that make the novel more interesting. You can check it out here: https://www.amazon.com/dp/B094NMRWPJ
I'm not really sure if this will work for you. Who knows, though. There is a political thriller based on both real and fictional events. It also tells about the assassinations, for example, Kennedy's. But it was not Oswald who killed him, it was a woman sniper. It also tells us about 9/11 and the like. You can get acquainted with it here https://www.amazon.com/dp/B094NMRWPJ. And there are also some reviews.
P.S. The book is not about maniacs or something like that, and the author is little known.