Young black men detained in Cook County, Chicago, face a higher mortality rate than the general population of the county, according to a bulletin [PDF] published by the federal Office of Juvenile Justice and Delinquency Prevention (OJJDP) as part of their “Northeastern Juvenile Project.”

The bulletin, titled “Violent Death in Delinquent Youth After Detention,” found that black women had even higher mortality rates compared to the rest of the county, and that homicides involving firearms were, by far, the leading cause of death.

The Northeastern Juvenile Project focused on 1,829 kids between the ages of 10-18 who had been incarcerated at the Cook County Juvenile Temporary Detention Center between 1995 and 1998. Researchers chose Cook County because of its size, diversity and urban setting. Sixty five individuals from that sample died during the follow-up period.

Studies have shown that “delinquent youth, who often are depicted as juvenile predators, are also at great risk for injury and early violent death,” the report states. “Offending increases exposure to life-threatening situations.”

Such experiences disproportionately affect African American youth. “The groups that are at greatest risk (racial and ethnic minorities, male youth, and urban youth) are all overrepresented in the juvenile justice system,” the authors write.

The mortality rate among formerly incarcerated youth was more than four times higher than that of the county’s general population, according to their research. Females, in particular, had a mortality rate eight times higher than that of the rest of Cook County.

The overwhelming majority of deaths in the sample were homicides, far outpacing rates for the rest of the population. 95.5% of deaths among those surveyed were homicides or ‘legal intervention,’ and 93% of those homicides involved firearms.

Other studies cited in the bulletin found 20% of deaths among all youth between 15–24 in the United States were from firearms. 66% of individuals in that age group killed by firearms nationwide in 2007 were African American or Hispanic.

Astonishingly, these numbers dwarfed those published by a previous study from 1997, conducted during a historic spike in homicides. “Although homicide rates have decreased among all racial/ethnic groups and ages since the mid-1990s,” the authors write, “African Americans (regardless of gender or age) still have the highest mortality rate by far.”