Today the CDC released its July 12, 2013 Mortality and Morbidity Weekly Report, which contains a report on Homicide Rates Among Persons Aged 10-24 Years - US - 1981-2010.   Among other findings are the following:

• Homicide disproportionately affects persons aged 10-24 years in the United States and consistently ranks in the top three leading causes of death in this age group, resulting in approximately 4,800 deaths and an estimated $9 billion in lost productivity and medical costs in 2010.
• Homicide rates varied substantially during the study period, with a sharp rise from 1985 to 1993 followed by a decline that has slowed since 1999. During the period 2000-2010, rates declined for all groups, although the decline was significantly slower for males compared with females and for blacks compared with Hispanics and persons of other racial/ethnic groups. 
• Among persons aged 10-24 years, males, those aged 20-24 years, and blacks had the highest rates of homicide over the 30 years examined (Figures 2 and 3). In 2010, the homicide rates for these groups were 12.7 per 100,000 for males, 13.2 for persons aged 20-24 years, and 28.8 for blacks.
• Homicide rates for males remained substantially higher than rates for females. Although model-estimated rates for males and females indicate declines, in relative terms, the decline for males was significantly slower than the decline for females (p=0.03).

The full report can be viewed here.