A general distribution patterns for murders is their frequent occurrence in the heavy business districts of large cities and in the low-grade residential areas around those business centers. The murder rate is higher in times of prosperity, and murders tend to occur within a small population subgroup where violence is an accepted response to frustration and perceived threats. Alcohol has also been found to play an important role in homicide. According to research findings murderers tend to have a childhood history of violence to fantasize less than the general population about anger, fear, and aggression. They rarely verbalize about feelings and they rarely exhibit classic mental illness at the time they kill. Murderers tend to be black males. The discussion also focuses on Wille's (1974) classification of murderers into 10 types, Resnick's (1969) study of parents who kill their children, Guttmacher's (1973) classification of murderers according to psychiatric diagnoses, and Lunde's (1976) distinction between the mass murderer and the serial murderer. Other research discussed includes Tanay's (1976) identification of three types of murderers, Abrahamsen's (1973) analysis of the psychological characteristics of murderers, psychological testing of murderers, and Revitch's (1975, 1977) classification system for environmentally stimulated homicides. Twenty-one references are listed.