This site from the Bureau of Justice Statistics provides a series of data charts that describe homicide patterns and trends in the United States since 1976. Coverage includes statistics on demographic trends by age, gender, and race; infanticide and eldercide; homicide of intimates and law enforcement officials; and trends by region, weapons, and urban population. Overview sections provide summaries of significant trends in these and other categories. One of the more dramatic findings: "the homicide victimization rate for 14-17 year-olds increased almost 150% from 1985 to 1993." The report is also available in .pdf format.