Actually it seems there are many sociopaths who do studies like doctors. Sure, its not common but it still exists.Both of these guys are novelists and what I have read of psychology studies the reality is quite much different. Very rarely there are people who kill for fun; usually the reasons are money, revenge or drug abuse. Of the remaining ones quite many are sociopaths which means they can't feel compassion. The latter group is the most dangerous to random people but also the smallest group in civilised world where social security and healthcare organisations take care of kids. Because becoming a sociopath requires normally the right genes but also it must be in combination with a very poor and abused childhood.
This is also the group where most serial killers come from. Serial killers get much publicity and even movies and TV series. In real life most serial killers come from the non-civilised and under developed countries like Russia and USA.
Anyway, we will have to wait for him to say anything about it, if he will.
I am disappointed he didn’t die in the hospital.