The Mystery of Why People Commit Crimes

     It’s like the old staple of 1930s gangster movies: why does one person become a criminal and the other a priest? Or from my perspective, why does one become a serial killer, another a rapist, another an assassin, another a bomber, a…

     It's like the old staple of 1930s gangster movies: why does one person become a criminal and the other a priest? Or from my perspective, why does one become a serial killer, another a rapist, another an assassin, another a bomber, another a poisoner, and yet still another a child molester? And within these crime categories, why does each commit his atrocities in the precise way he does? The answer lies in one fundamental question that applies to every one of them:
     Why did he do it?
     The who? follows from there.
     That's the mystery we have to solve.

John Douglas [criminal profiler] and Mark Olshaker, The Anatomy of Motive, 1999

from http://jimfishertruecrime.blogspot.com/