Samuel Yochelson, Ph.D., M.D., was until his death in 1976, director of the Program for the Investigation of Criminal Behavior at Saint Elizabeths Hospital, Washington, D.C. and research professor of clinical psychiatry at George Washington University School of Medicine Stanton E. Samenow, Ph.D., is a clinical psychologist in Alexandria, Virginia. He is also the co-author of The Criminal Personality, Volume II: The Change Process, and The Criminal Personality: Volume I, A Profile for Change.