An investigation finds that prosecutors vary widely in deciding whether to file charges when children get ahold of a gun and accidentally shoot themselves or another child.

Research by The Associated Press and the USA TODAY Network reveals that adults are not always held accountable when those shootings are fatal.

That is true even in cases with similar circumstances in which firearms were stored irresponsibly. A shooting that leads to a prison sentence in one state can end with no prosecution at all in another.

Some prosecutors say parents or guardians have been punished enough by the loss of a child

The news organizations found that children under age 12 die from gun accidents in the U.S. about once a week.