The statistical study of homicide in California focuses on sources of data, methods of committing homicide, and homicide death rates by sex, race, and age. Findings show that homicide deaths are an increasing public health problem, with the most alarming increases in victimizations occurring among the elderly and very young children. The rate of homicide is highest among black males, and guns are the weapons most frequently used. Little attention, however, has been given to the analysis of homicide with a view toward developing prevention approaches. The psychological "autopsy/biopsy" developed by Shneidman is important for developing information relevant to prevention approaches. The psychological autopsy involves talking to survivors and knowledgeable acquaintances of the victim so as to reconstruct the victim's lifestyle, thoughts, fantasies, and behaviors relating to his/her death. The psychological biopsy is used for the perpetrator to better understand the dynamics of the homicide trajectory, not only from the murderer's perspective but from the perspectives of the significant others in his/her life. Prevention efforts must target the young and be transmitted through community organization and education. They further involve social problemsolving, prison reform, improved police-community relations, better coordination among concerned agencies, and educating politicians to take a more active role in prevention efforts. Also, research in suicidology has implications and correlations for homicide prevention. The most translatable concepts are prevention, intervention, and postvention; clues to homicide (verbal, behavioral, and situational); lethality and the identification of high-risk groups; and the use of the psychological autopsy for victims and psychological biopsy perpetrators. Specific approaches for homicide prevention efforts are described in outline. Tabular data and 19 references are provided.