I also have a selfish motivation for wanting these maniacs studied.
I am a high-functioning autistic person. I work in the medical field, I'm a published writer, and I have a clean record.
Yet I've been denied jobs (and have filed lawsuits . . . some of which I've won) because people believe autistic people are dangerous, so I shouldn't be "allowed" to work in certain jobs, and that--because of my autism--I'm not worthy of trust.
Jeffrey Dahmer, Nikolas Cruz, Adam Lanza, and Ted Kaczynski were all mass shooters, bombers, serial killers, etc. who are claimed to be autistic, so I shouldn't be allowed to work at a job like everyone else because people with high-functioning autism are "dangerous" and "can snap at any second" . . . so I always have to fight in the legal arena for everything. This is despite having an immaculate record, and passing a background check for my CCW (with fingerprints and everything).
So yes, I have selfish motives for wanting a better understanding of these murderers . . . although I still think that everyone would benefit.