Way back in June, Brad Heath of USA Today did some excellent work reporting on dozens of federal prisoners serving sentences for federal gun laws that it turns out they didn’t actually violate. Federal law prohibits convicted felons from owning guns. But North Carolina’s complex sentencing system makes a mess of an attempt at creating federal gun-ownership guidelines. As a result, USA Today determined there were about 60 men in federal prisons for owning guns, even though their previous crimes weren’t serious enough to be considered felonies.

Heath follows up today with a combination of bad news and good news. The bad news is that the number is higher: About 175 federal prisoners may have been improperly imprisoned or sentenced. The good news is the federal government is actually responding to try to fix the situation:

USA TODAY's investigation in June identified 60 people imprisoned even though a U.S. appeals court said what they had done was not a federal crime. Still, Justice Department lawyers did almost nothing to notify prisoners — many unaware they were innocent — and asked federal judges to keep them locked up anyway. The department reversed that position in August.

Since then, federal judges have ordered the government to free at least 32 prisoners, and have taken 12 more off post-prison supervision, court records show. Some had served up to eight years before they were freed.

It’s an important reminder for anybody looking to the federal government to cobble together some sort of “fix” to keep bad people (whoever those might be) from getting guns. Even legislation as seemingly simple as forbidding felons from owning guns has unintended consequences when applied to a host of state and municipal laws.