““It's what we are. There was something inherent, deep within the criminal's mind and psyche, that compelled him to do things in a certain way. Later, when I started research into the minds and motivations of serial murderers, then, when I began analyzing crime scenes for behavioral clues, I would look for the one element or set of elements that made the crime and the criminal stand out, that represented what he was. Eventually, I would come up with the term signature to describe this unique element and personal compulsion, which remained static. And I would use it as distinguishable from the traditional concept of modus operandi, which is fluid and can change.””
