Paul E. Mullen is a world authority on lone wolf mass killers and stalking. He is Professor Emeritus at Monash University, and has held prominent posts at the Institute of Psychiatry in London and the Victorian Institute of Forensic Psychiatry in Australia. He has published more than 200 journal articles and co-authored four books on forensic psychiatry, including a leading textbook on stalking that was awarded the American Psychiatric Association's Guttmacher Prize.