This prospective, longitudinal study examined mortality rates among 1,829 young people (1,172 male and 657 female) enrolled in the Northwestern Juvenile Project, a study of health needs and outcomes for delinquent youths. The participants, aged 10 through 18, were randomly sampled from intake at the Cook County Juvenile Temporary Detention Center in Chicago between 1995 and 1998. As of March 31, 2004, the researchers had monitored participants for an average of 7.1 years. Data on deaths were obtained from family reports or records and verified by the local medical examiner or the National Death Index.

The study found that 65 young people died during the follow-up period, all from causes other than illness. In 95.5 percent of the deaths, the cause was homicide or injuries resulting from a police officer's apprehension efforts; 1.1 percent were suicides; 1.3 percent were from motor vehicle accidents; 0.5 percent were from other accidents; and 1.6 percent were from other external causes. Among homicides, 93 percent were from gunshot wounds.

The overall mortality rate was more than four times greater than the rate in the general population, even after controlling for differences in gender, racial and ethnic groups and age. Additionally, the mortality rate for females was nearly eight times greater than that of the general population.