comfortable by actually loosening some of the binds around their hands and feet. >> tried to comfort them as much as i could. >> to keep them quiet or because you were worried? >> both. i'm not a bad guy. i care for people. have concerns for people. and i hadn't really crossed that path yet where i was going to kill the people yet. i was in concern mode. >> what you're seeing here is a very early form of a future serial killer. who's still trying to decide what it is he's going to get out of these crimes. >> we asked james allen fox, one of the nation's leading criminologists and a professor at northeastern university, to give his analysis of this interview. he has studied serial killers for 25 years and has written numerous books. his most recent book, on serial killers including btk. >> he wants to fulfill his fantasy. but it's not necessary for them to feel excessive suffering.