ELIZABETHTOWN, N.C. – Terrell McCullum did not commit a federal crime by carrying a shotgun and a rifle out of his ex-girlfriend's house.

But he is serving a federal prison sentence for it. And the fact that everyone — including the U.S.Justice Department— agrees that he is legally innocent might not be enough to set him free.

A USA TODAY investigation, based on court records and interviews with government officials and attorneys, found more than 60 men who went to prison for violating federal gun possession laws, even though courts have since determined that it was not a federal crime for them to have a gun.

Many of them don't even know they're innocent.

The legal issues underlying their situation are complicated, and are unique to North Carolina. But the bottom line is that each of them went to prison for breaking a law that makes it a federal crime for convicted felons to possess a gun. The problem is that none of them had criminal records serious enough to make them felons under federal law.

Still, the Justice Department has not attempted to identify the men, has made no effort to notify them, and, in a few cases in which the men have come forward on their own, has argued in court that they should not be released.

Justice Department officials said it is not their job to notify prisoners that they might be incarcerated for something that they now concede is not a crime. And although they have agreed in court filings that the men are innocent, they said they must still comply with federal laws that put strict limits on when and how people can challenge their convictions in court.

"We can't be outcome driven," said Anne Tompkins, the U.S. attorney in Charlotte. "We've got to make sure we follow the law, and people should want us to do that." She said her office is "looking diligently for ways, within the confines of the law, to recommend relief for defendants who are legally innocent."

These cases are largely unknown outside the courthouses here, but they have raised difficult questions about what, if anything, the government owes to innocent people locked in prisons.

"It's been tough," said Ripley Rand, the U.S. attorney in Greensboro, N.C. "We've spent a lot of time talking about issues of fundamental fairness, and what is justice."

It's also unusual. Wrongful conviction cases are seldom open-and-shut — usually they depend on DNA or other new evidence that undermines the government's case, but does not always prove someone is innocent. Yet in the North Carolina gun cases, it turns out, there simply were no federal crimes.

Using state and federal court records, USA TODAY identified 23 other men who had been sent to federal prison for having a firearm despite criminal records too minor to make that a federal crime. Nine of them remain in prison, serving sentences of up to 10 years; others are still serving federal probation. The newspaper's review was limited to only a small fraction of cases from one of the three federal court districts in North Carolina.

Federal public defenders have so far identified at least 39 others in additional court districts, and are certain to find more. And prosecutors have already agreed to drop dozens of cases in which prisoners' convictions were not yet final.

Some of the prisoners USA TODAY contacted — and their lawyers — were stunned to find out that they were imprisoned for something that turned out not to be a federal crime. And their lawyers said they were troubled by the idea that innocence alone might not get them out.

"If someone is innocent, I would think that would change the government's reaction, and it's sad that it hasn't," said Debra Graves, an assistant federal public defender in Raleigh. "I have trouble figuring out how you rationalize this. These are innocent people. That has to matter at some point."

WHO CAN HAVE A GUN?

Terrell McCullum conceded in interviews that he has made plenty of bad decisions — including having the two guns that sent him to federal prison. But there is little dispute that his criminal record wouldn't now be serious enough to make having the guns a federal crime.

Even so, government lawyers have said in court filings that he should remain in the Farmville, Va., jail where he is serving the end of his federal sentence.

"At most," the Justice Department said in an April court filing, McCullum "has become legally innocent of the charge against him." In other words, the law may have changed, but the facts of his case didn't — he did possess the gun, and he had a criminal record — so he isn't entitled to be released.

His request to be released is still pending. "I don't know what's going to happen," McCullum said during a recent phone call. "I'm just praying on it."

The key to McCullum's innocence lies at the complicated intersection of state and federal criminal laws.

Decades ago, Congress made it a federal crime for convicted felons to have a gun. The law proved to be a powerful tool for police and prosecutors to target repeat offenders who managed to escape stiff punishment in state courts. In some cases, federal courts can put people in prison for significantly longer for merely possessing a gun than state courts can for using the gun to shoot at someone.

To make that law work in every state, Congress wrote one national definition of who cannot own a gun: someone who has been convicted of a crime serious enough that he or she could have been sentenced to more than a year in prison.

Figuring out who fits that definition in North Carolina is not as simple as it sounds. In 1993, state lawmakers adopted a unique system called "structured sentencing" that changes the maximum prison term for a crime, based on the record of the person who committed it. People with relatively short criminal records who commit crimes such as distributing cocaine and writing bad checks face no more than a few months in jail; people with more extensive records face much longer sentences.

For years, federal courts in North Carolina said that did not matter. The courts said, in effect: If someone with a long record could have gone to prison for more than a year for the crime, then everyone who committed that crime is a felon, and all of them are legally barred from possessing a gun.

Last year, the U.S. Court of Appeals for the 4th Circuit said federal courts (including itself) had been getting the law wrong. Only people who could have actually faced more than a year in prison for their crimes qualify as felons under federal law.

The 4th Circuit's decision came in a little-noticed drug case, United States v. Simmons, but its implications could be dramatic. For one thing, tens of thousands of people in North Carolina have criminal records that no longer make having a gun a federal crime. About half of the felony convictions in North Carolina's state courts over the past decade were for offenses that no longer count as felonies under federal law.

No one yet knows precisely how many people were incorrectly convicted for having a gun, but the number could be significant. Rand, the U.S. attorney in Greensboro, estimated that more than a third of the gun cases his office prosecuted might be in question, either because the defendants didn't commit a federal crime at all by possessing a gun or because their sentences were calculated incorrectly.

"We're going to be addressing this for a while," he said.

The Justice Department and federal courts moved quickly to clean up cases that were pending when the 4th Circuit announced its decision. Prosecutors dropped pending charges against people whose records no longer qualified them as felons; the 4th Circuit reversed convictions in more than 40 cases that were on appeal at the time. Some of the men were given shorter sentences; others were simply let go.

But the next question has proved far harder to answer: What should the government do with the prisoners whose legal cases were already over?

STILL LOCKED UP

The men in McCullum's position have little hope of inspiring much public sympathy. All had racked up at least modest criminal records, frequently for selling drugs. Many only wound up in federal court because police had already arrested them for breaking state laws (including a state law, not affected by the 4th Circuit's ruling, barring them from having guns).

One man went to federal prison after a shootout; another led police officers on a high-speed chase. One shot a police dog.

McCullum hadn't done anything so serious.

His mother, Rebecca Farris, concedes he had a knack for getting in trouble, but said he's still "softhearted." McCullum, now 26, has been diagnosed as mentally disabled, and quit school in the 11th grade after he was kicked out for fighting.

On a recent afternoon, Elizabethtown Police Chief Bobby Kinlaw squinted at the computer in his small office and rattled through an inventory of McCullum's frequent encounters with his officers, including arrests for larceny, fighting, making threats and driving without insurance. "He seemed to be on the radar on a regular basis," Kinlaw said.

McCullum's most serious scrape with the law came in September 2007, when he pleaded guilty to stealing a gun and was put on probation. Under North Carolina law, he could have been sentenced to no more than 10 months in prison.

A month later, McCullum broke up with his girlfriend and came to her small house to collect his things. The two quickly got into an argument, and McCullum knocked over a cocktail table and yanked a telephone cord out of the wall, Kinlaw said. His ex-girlfriend's son called the police, and an officer waited outside to keep the peace while McCullum carried his belongings out to his truck. He carried out his clothes. Then, while the officer watched, he carried out a .22-caliber rifle and a shotgun.

Police checked the guns' serial numbers and learned the shotgun had been reported stolen, so they arrested McCullum. (They didn't realize until later that the gun had been stolen nine years earlier, by someone else, when McCullum was 12.) When they found out McCullum had a criminal record, they charged him with possession of a firearm by a felon, and turned the case over to the federal government.

McCullum says the guns weren't loaded, and he insists he didn't know he wasn't supposed to have firearms. He kept them because they had belonged to his grandfather.

In 2009, McCullum went to federal court and pleaded guilty to the charge of illegally possessing a firearm. At the time, even his lawyers thought that his prior conviction for stealing a gun made him a felon under federal law. The judge sentenced him to a year and a day in custody, and the government sent him to Big Sandy, a high-security penitentiary in the mountains of eastern Kentucky.

It was the first time McCullum had been to prison.

"I ain't no bad person. I made mistakes, but I ain't that bad," McCullum said. "I just was young back then, just made some stupid mistakes."

He got out in 2010 but quickly violated his supervised release by robbing a man. ("I saw him with a whole bunch of money and I just got him like that," McCullum said during one phone call.) The judge sent him back to prison. Now he's finishing his sentence at the local jail in Farmville, counting the days until he can go home.

SHUT OUT OF COURT?

Whether McCullum — or the dozens of others like him — can go home depends on federal laws that put strict limits on when and how people who have already been convicted of a crime can come back to court to plead their innocence.

Those laws let prisoners challenge their convictions if they uncover new evidence, or if the U.S. Supreme Court limits the sweep of a criminal law. But none of the exceptions is a clear fit, meaning that, innocent or not, they may not be able to get into court at all. Federal courts have so far split on whether they can even hear the prisoners' cases.

Habeas corpus — the main legal tool for challenging unlawful detention — is currently ill-suited to such cases, said Nancy King, a Vanderbilt Law School professor who has studied the issue. Habeas mainly safeguards people's constitutional right to a fair process, she said, and the problem is that "saying, 'I'm innocent' isn't, on its face, that type of constitutional claim."

Still, she said, "innocent people should be able to get out of prison."

Prosecutors don't disagree, though most said they are not convinced the law allows it.

Rand, the U.S. attorney in Greensboro, said he is "not aware of any procedural mechanism by which they can be afforded relief," though he said lawyers in his office "have not been pounding on the table" to keep the men in jail.

"No one wants anyone to spend time in jail who should not be there," said Thomas Walker, the U.S. attorney in Raleigh. That's why he said prosecutors were quick to dismiss charges that were pending when the 4th Circuit ruled. But cases in which convictions are already final "are in a totally different posture and require us to follow the existing statutory habeas law," he said.

But there's also an even more basic question: How would the prisoners even know?

Rand said he personally reviewed all of the gun-possession cases his office had filed in recent years, often bringing home stacks of documents to examine after his kids went to bed. A former state judge, he figured he would have the easiest time identifying problems. Some of the cases he looked at, he said, would no longer qualify as federal crimes.

But he said he did not notify those defendants.

Instead, courts have asked public defenders to seek them out. Those lawyers said the Justice Department should do more to help, because it has better information and more resources, an assertion prosecutors dispute.

"We're doing it with our hands tied," said Eric Placke, a federal public defender in Greensboro. "I appreciate the compelling considerations they have to deal with. But I do think in cases of actual innocence that it would be nice, to say the least, if they would be a little more proactive."

Placke and other public defenders said the reviews have been difficult because they often have limited access to records from the men's prior convictions, which has left them to hunt through files in courthouses across the state.

USA TODAY conducted a similar, though far more limited review, examining every gun conviction in western North Carolina between 2005 and 2011. The review was limited to people who had been convicted only of gun possession, and included only those cases in which federal prosecutors had specifically identified the prior offense that made possession a crime. USA TODAY used state court records to find those cases in which the men's prior convictions were, in hindsight, not serious enough to convict them of the federal crime.

'A BETTER LIFE'

Travis Bowman said he "got cold chills" when USA TODAY told him that he's innocent of the gun charge that landed him in a federal prison in Coleman, Fla., for 10 years. He said he'd never considered the possibility that what he did wasn't a federal crime. He pleaded guilty to illegally possessing a sawed-off shotgun.

He's not scheduled to get out of prison until 2016.

Police arrested Bowman in 2007 after a 110-mph chase through Murphy, N.C. It began when North Carolina Highway Patrol Sgt. Chris Wood pulled Bowman over for speeding, planning only to write him a warning. But a routine records check showed Bowman had been affiliated with a gang known as Folk Nation, and that he was wanted in Georgia. "I got a real eerie feeling," Wood said. He drew his gun and told Bowman to put his hands on the steering wheel.

Bowman took off.

With his pregnant, 15-year-old girlfriend in the seat next to him, he raced down the highway, swerved through a McDonald's parking lot and collided with four police cars. He didn't stop until his girlfriend threw the speeding car into park.

State officials didn't prosecute Bowman for the shotgun, or for the chase, or for crashing into the police cars, or for refusing to let his girlfriend out of the car. Instead, they turned the case over to the Justice Department, which sent him to prison for a decade just for having an unloaded shotgun on the floor behind the passenger seat. (Bowman said he was taking the gun to his brother.)

But Bowman's prior convictions — for habitual misdemeanor assault and having drugs in prison — aren't serious enough to make owning the gun a federal crime. Neither could have put him in prison for more than a year.

Bowman says he plans to ask a federal judge to declare him innocent and let him out.

"Hopefully I'll get the chance to be out there soon," Bowman wrote in an e-mail."I just want a better life than this. I have to prove to a lot of people that I'm not the old me. I want to be a person my kids will look up to and be proud of."

Going home is far from a safe bet. Even if a court ultimately decides to let Bowman out, he could still face all the charges state officials dropped when his case went to federal court.