In February 1994, the Federal Brady Handgun Violence Prevention Act established a nationwide requirement that licensed firearms dealers observe a waiting period and initiate a background check for handgun sales. The study analyzed relevant vital statistics for the United States in the years 1985 through 1997; these data were obtained from the National Center for Health Statistics. Total and firearms homicide and suicide rates per 100,000 adults and proportion of homicides and suicides that resulted from firearms were calculated by State and year. Controlling for population age, race, poverty, and income levels; urban residence; and alcohol consumption, the 32 "treatment" States directly affected by the Brady Act requirements were compared with the 18 "control" States and the District of Columbia, which had equivalent legislation already in place. Findings show that changes in rates of homicide and suicide for treatment and control States were not significantly different, except for firearm suicides among persons aged 55 years or older. This reduction in suicides for this age group was much stronger in States that had instituted both waiting periods and background checks than in States that only changed background check requirements. The authors advise, however, that the pattern of implementation of the Brady Act does not permit a reliable analysis of a potential effect of reductions in the flow of guns from treatment-State gun dealers into secondary markets. 2 figures, 1 table, and 40 references