A three year study, based on certain control factors, of 51 murderers, was undertaken to determine- if possible- any predominant pattern, and while it is by no means psychoanalytical (Robert Lindner; more recently Manfred Guttmacher's The Mind of a Murderer) it is certainly based on psychological premises and particularly on the frustration-aggression hypothesis. Some of the case histories, along with the extensive interviewing of the murderer's mother and control comparison with a brother, are included. Certain common features emerge: murderers usually kill relatives or acquaintances, usually in the heat of argument, usually in the summer; most of them experienced far greater physical frustration (birth trauma, diseases, accidents, beatings, etc.) than normal-- and psychological frustration (from parental attitudes, training, treatment). One can conclude, after this exploratory study, that murder is most frequently an aggression release, and there are preventive and rehabilitative suggestions to follow. For those interested in the behavioral aspects of crime, whether professionally or otherwise, this couples scientific methods with the author's longstanding interest in the field.