The U.S. child gun death data includes 18 and 19 year olds, which legally are adults. Most 18 and 19 year old gun deaths are gang/drug related, not school shootings. Many child deaths are collateral to gang shooting in Chicago, Baltimore, etc.
If one removes the gun deaths from the five 5 cities with the most gun deaths, the national homicide rate drops enormously. Those five cities are in states with stricter gun laws.
Gun free zones are hazardous to your health.
Five major U.S. cities are hazardous to your health.