THE FOCUS IS ON SIMILARITIES AND DIFFERENCES IN CIRCUMSTANCES SURROUNDING CRIMINAL HOMICIDE IN TERMS OF THE USE OF FIREARM AS HOMICIDE WEAPONS AND OF THE INTERPERSONAL RELATIONS BETWEEN KILLER AND VICTIM. STUDIES BY AMERICAN CRIMINOLOGISTS SUCCEEDED IN SHOWING CORRELATIONS BETWEEN TYPES OF WEAPONS USED IN HOMICIDE AND RACE AND SEX OF KILLERS, BUT CORRELATIONS BETWEEN GUN AVAILABILITY AND HOMICIDE INCIDENCE REMAIN DIFFICULT TO PROVE. ONE POSSIBLE CORRELATION COULD BE THAT FIREARMS CAUSE MORE DEATHS THAN OTHER TYPES OF WEAPONS. IN MEXICO FIREARMS ARE THE MOST WIDELY USED HOMICIDE WEAPONS, BUT NOT IN BRAZIL OR IN ENGLAND. INSOFAR AS VICTIM-OFFENDER RELATIONSHIPS INFLUENCE HOMICIDE MOTIVATION, RESEARCH HAS SHOWN THAT IN MOST COUNTRIES KILLERS AND VICTIMS ARE EITHER RELATED OR INTIMATELY ACQUAINTED. COMPARISON OF HOMICIDE MOTIVES IN DIFFERENT COUNTRIES AND SOCIOCULTURAL ENVIRONMENTS INDICATES THAT THE MOST FREQUENT HOMICIDE MOTIVES, CLASSIFIED BY COUNTRY, INCLUDE DOMESTIC QUARRELS IN ENGLAND AND DENMARK; HONOR MOTIVES IN BRAZIL; THE CULMINATION OF LONG-STANDING FEUDS IN INDIA (WHERE PEOPLE APPEAR TO BE GENERALLY MORE PATIENT AND LESS VIOLENT). INTERNATIONAL COMPARISONS OF OTHER CIRCUMSTANCES SURROUNDING THE PERPETRATION OF CRIMINAL HOMICIDE INDICATES: HOMOGENEITY OF SEX, RACE, AND SOCIAL CLASS OF KILLER AND VICTIM IN THE UNITED STATES AND BRAZIL; HOMOGENEITY OF SOCIAL CLASS ONLY IN ENGLAND; HOMOGENEITY OF RELIGION, CASTE, AND SEX IN INDIA. HOMICIDE CAUSES APPEAR TO BE RELATED TO THE PREVALENCE OF CERTAIN SOCIAL VALUES IN DIFFERENT COUNTRIES, THE MODIFICATION OF WHICH MAY REDUCE THE INCIDENCE OF VIOLENT CRIME, INCLUDING HOMICIDE, SINCE HOMICIDE IS CHIEFLY A CRIME OF PASSION AND IS HARD TO CONTROL BY LEGAL MEANS. A DEFINITE CORRELATION BETWEEN AVAILABILITY OF FIREARMS AND HOMICIDE HAS NOT BEEN ESTABLISHED. --IN SPANISH.