The Associated Press and USA TODAY Network found that even among cities with high levels of gun violence, these are the few where the teen hazard rate stands out.
To examine the issue of youth gun violence, the reporters used data from the Gun Violence Archive to isolate incidents in which a minor age 12 to 17 was either killed or injured.
The incidents were aggregated at a city level and then measured against the population in that age group to derive a "hazard rate" — the percentage of minors ages 12 to 17 in the city injured or killed in gun violence each year.
The population figures for 12- to 17-year-olds were based on 2010 U.S. Census Bureau estimates for legally incorporated "Place" entities. The incident data from the Gun Violence Archive was collected through that organization's monitoring of media and police reports across the country.
GVA is a nonpartisan, nonprofit organization that catalogues incidents of gun crime across the United States. The data used in the analysis spans 3½ years, from the start of 2014 through June 30, 2017.
The AP and USA TODAY Network analysis found that with the exception of Chicago, the cities with the highest youth hazard rates were nearly all similar in size — with populations of 50,000 to 500,000, based on 2016 Census population estimates.
The analysis found there are a half-dozen cities with particularly high youth hazard rates: Wilmington, Delaware; Chicago; Savannah, Georgia; Trenton, New Jersey; New Orleans; and Syracuse, New York. Wilmington, in particular, had a youth hazard rate nearly double that of any other city.
Several other smaller and mid-sized cities also showed high levels of teenage gun violence, but the rates began to level out after the top six.
Smaller cities naturally show higher variation than larger cities, but these six municipalities had such outsize youth hazard rates compared to others that it was clear teenage gun violence was a problem.
The AP and USA TODAY Network analysis also tested the youth hazard rate against the adult hazard rate to make sure the youth rate was unusually high, instead of just being a result of GVA's data-collection quality in certain cities.
GVA employs a team of people to help maintain its database, but could miss incidents for a variety of reasons. Those could include lack of publicity or coverage of a crime, or police departments mistakenly categorizing gun-related crimes as other types of incidents.
In doing this test, reporters found that Wilmington was one of roughly a dozen cities in the U.S. with a high overall per-capita gun crime rate.
Despite that, Wilmington's hazard rate for 12- to 17-year olds was still 60 percent higher than its adult rate, indicating that teens, in particular, faced a specific threat of gun violence.
Among the other five cities whose youth hazard rate stuck out, all save for New Orleans had a much higher rate for teens than for adults. In New Orleans, the rates for the two groups were the same.