No, I wouldn't call them a friend. It ends at sympathy for some of the guys.
BTK: http://www.amazon.com/Inside-Mind-BTK-Thirty-Year-Notorious/dp/0470325151
Casey Anthony (less about the murder and more focused on the trial. ) http://www.amazon.com/Imperfect-Justice-Prosecuting-Casey-Anthony/dp/B009JS6GUM/ref=sr_1_1?s=books&ie=UTF8&qid=1368819702&sr=1-1&keywords=casey+anthony
And, my hands down favorite:http://www.amazon.com/John-Wayne-Gacy-Defending-Monster/dp/1620870711/ref=sr_1_1?s=books&ie=UTF8&qid=1368819746&sr=1-1&keywords=gacy