The Times is publishing a series of reports highlighting common laws and rules. Today, we examine a recent U.S. Supreme Court decision that could take away the guns of some convicted people who thought they could legally have guns. To suggest a law for The Times to highlight, contact the writer.

VALPARAISO | Over the years, thousands of region residents charged with domestic battery -- even for something as simple as slapping the person with whom they live -- have agreed to plead guilty to battery instead of domestic battery to avoid losing the right to possess guns.

But they now face some bad news.

The U.S. Supreme Court recently decided -- in the case of United States v. Randy Edward Hayes -- that even if a person's conviction isn't labeled domestic battery, if the underlying facts show that domestic violence occurred, the person can't possess firearms. The decision could have a major effect locally and nationally.

Valparaiso attorney Bryan Truitt estimates there have been 5,000 Northwest Indiana cases since 1996 involving people who pleaded guilty to a lesser offense in order to keep their guns so they could, for instance, continue to hunt game or work their job as a security guard.

All of those people now could face federal charges of illegal gun possession and lose the right to have guns.

"This is a practical nightmare," Truitt said, adding that many gun owners probably are unaware of the court decision and could become ensnared by it.

The problem with the decision, Truitt said, is it treats people involved in minor one-time battery offenses the same as dangerous and unbalanced people who legitimately should not have guns.

The federal Gun Control Act of 1968 prohibits felons from possessing firearms, and in 1996 Congress extended the prohibition to include people convicted of misdemeanor domestic battery.

Truitt said Hayes was convicted of simple battery in 1994, and it was not labeled domestic battery. In 2005, police were called to his house, and they found a rifle. Hayes was charged federally with being a prohibited person in possession of a firearm. He moved to dismiss the charge because he was not convicted of domestic battery.

"The Supreme Court essentially held that it does not matter what label is on the crime of conviction. What matters is the underlying facts," Truitt said.

Truitt said the Supreme Court decision opens up the possibility that convictions of disorderly conduct, intimidation, invasion of privacy and other charges unknowingly could place people who thought they could have guns in jeopardy of federal prosecution.

Also, the thousands of people who could have fought the battery charges against them now are stuck because they pleaded guilty with the understanding they could keep their guns, Truitt said.

The only gun that felons and batterers can have, according to federal law, is a black powder rifle. But Indiana law prohibits serious violent felons from having even those weapons.