This sounds like a fiction premise.  It's almost too ridiculous to be true: A teenager gets into a serious accident at summer camp and nearly dies.  Upon awakening, he has changed.  He needs to relearn absolutely everything, incluging how to eat, how to walk, how to live life again. He has a uncontrollable rage, managed only by intense medication.  He loses all his friends, and retreats to books and the internet. There, he becomes obsessed with serial killers, and on a whim, he writes one a letter.  They reply


This isn't fiction.  Tony Ciaglia really found himself in exactly this position, and placed himself as the only friend to some of the US's worst killers.  Over the course of his correspondence, he tries to draw out more information about their crimes, and even tries to elicit more confessions, information and locations of undiscovered victims.  He even goes to visit some of these killers in prison, and discovers that not all of them are as friendly as they seem. (They are killers, after all.  Who'd have guessed?)

The book includes transcripts (odd misspellings included) of the letters the killers wrote, and many of them are disturbing.  It's a fascinating look into their minds, with their rationalizations for what they did.  While I wouldn't recommend this to just any kid because of the occasionally gruesome tidbits, older teens would certainly find it intriguing.