Fascinating. I read a book about him a few years ago called "Anyone You Want Me To Be: A True Story of Sex and Death on the Internet" by John Douglas.
http://www.trutv.com/library/crime/serial_killers/predators/john_robinson/index.html
The story continues on that site if you'd like to read it. If you ever want to borrow my book, let me know.In the end, picking the wrong sex partner brought the downfall of John E. Robinson, Sr., and exposed one of the most bizarre and lengthy homicidal careers in American criminal history.
The Midwestern serial killer, whose brutal treatment of his sometimes willing victims stands in stark contrast to his benign, fleshy appearance, sits on death row in Kansas facing execution for two murders (and a life sentence for a third). The 59-year-old grandfather also admitted to five slayings in Missouri, which accepted the guilty pleas in return for taking a pass on the chance to execute him.