Alan Simons was enjoying a Sunday morning bicycle ride with his family in Asheville two years ago when a man in an SUV suddenly pulled alongside him and started berating him for riding on the highway.

Simons, his 4-year-old son strapped in behind him, slowed to a halt. The driver, Charles Diez, an Asheville firefighter, stopped as well. When Simons walked over, he found himself staring down the barrel of a gun.

"Go ahead, I'll shoot you," Diez said, according to Simons. "I'll kill you."

Simons turned to leave but heard a deafening bang. A bullet had passed through his bike helmet just above his left ear, barely missing him.

Diez, as it turned out, was one of more than 240,000 people in North Carolina with a permit to carry a concealed handgun. If not for that gun, Simons is convinced, the confrontation would have ended harmlessly.

Diez, then 42, eventually pleaded guilty to assault with a deadly weapon with intent to kill.

Across the country, it is easier than ever to carry a handgun in public. Prodded by the gun lobby, most states, including North Carolina, now require only a basic background check, and perhaps a safety class, to obtain a permit.

In state after state, guns are being allowed in places once off-limits, like bars, college campuses and houses of worship. And gun rights advocates are seeking to expand the map still further, pushing federal legislation that would require states to honor other states' concealed weapons permits. The House approved the bill last month; the Senate is expected to take it up next year.

The bedrock argument for this movement is that permit holders are law-abiding citizens who should be able to carry guns in public to protect themselves.

"These are people who have proven themselves to be among the most responsible and safe members of our community," the federal legislation's author, Rep. Cliff Stearns, R-Fla., said on the House floor.

To assess that claim, The New York Times examined the permit program in North Carolina, one of a dwindling number of states where the identities of permit holders remain public. The review, encompassing the past five years, offers a look at how a liberalized concealed weapons law has played out in one state. And while it does not provide answers, it does raise questions.

Permit holders charged

Of the more than 240,000 people in North Carolina with a permit to carry a concealed handgun, more than 2,400 were convicted of felonies or misdemeanors, excluding traffic-related crimes, over the five-year period, The Times found when it compared databases of recent criminal court cases and licensees. While the figure represents a small percentage of those with permits, more than 200 were convicted of felonies, including at least 10 who committed murder or manslaughter. All but two of the killers used a gun.

More than 200 permit holders were also convicted of gun- or weapon-related felonies or misdemeanors, including roughly 60 who committed weapon-related assaults.

In about half of the felony convictions, the authorities failed to revoke or suspend the holder's permit, including for cases of murder, rape and kidnapping. The apparent oversights are especially worrisome in North Carolina, one of about 20 states where anyone with a valid concealed handgun permit can buy firearms without the federally mandated criminal background check. (Under federal law, felons lose the right to own guns.)

In Waxhaw, Ricky Wills, 59, kept his permit after recently spending several months behind bars for terrorizing his estranged wife and their daughter in May with a pair of guns and then shooting at their house while they, along with a sheriff's deputy who had responded to a 911 call, were inside.

"That's crazy, absolutely crazy," his wife, Debra Wills, said in an interview when told that her husband could most likely still buy a gun in the state.

Soon after the shooting, Wills' wife obtained a restraining order, which also should have led to his permit being suspended.

Wills' permit was revoked this month, after The Times informed the local sheriff's office.

Sgt. Lori Pierce, who handles concealed handgun permits in Union County, said no one ever notified her about Wills, who was released from prison in November. And as the sole person handling permits in her county, she said, she does not have time to conduct regular criminal checks on permit holders, unless they are up for a five-year renewal.

As it is, she said, she can barely keep up with issuing permits. She has granted about 1,300 this year.

Growing national trend

U.S. gun laws vary, but, in most states, people do not need a license to keep firearms at home. Although some states allow guns to be carried in public in plain sight, gun rights advocates have mostly focused their efforts on expanding the right to carry concealed handguns.

The national movement toward more expansive concealed handgun laws began in earnest in 1987, when Florida started a "shall issue" permit process, in which law enforcement officials are required to grant the permits as long as applicants satisfy certain basic legal requirements.

The authorities in shall-issue states deny permits to certain applicants, such as convicted felons and people who have been involuntarily committed to a mental health institution, unless their gun rights have been restored. North Carolina, which enacted its shall-issue law in 1995, also bars applicants who have committed violent misdemeanors and has a variety of other disqualifiers; it also requires enrollment in a gun safety class.

Today, 39 states either have a shall-issue permit process or do not require a permit at all to carry a concealed handgun. Ten others are "may issue," meaning law enforcement agencies have discretion to conduct more in-depth investigations and exercise their judgment.

For now, the permits are good only in the holder's home state, as well as others that recognize them. The bill in Congress would require that permits be recognized everywhere.

In recent years, a succession of state legislatures have also struck down restrictions on carrying concealed weapons in all sorts of public places. North Carolina this year began allowing concealed handguns in local parks, and next year the legislature is expected to consider permitting guns in restaurants.

Falling through the cracks

Gun rights advocates in North Carolina, as well as elsewhere, often point to the low number of permit revocations as evidence of how few permit holders break the law. Yet permits were often not suspended or revoked in North Carolina when they should have been.

Charles Dowdle of Franklin was convicted of multiple felonies in 2006 for threatening to kill his girlfriend and chasing her to her sister's house, where he fired a shotgun round through a closed door. He then pointed the gun at the sister, who knocked it away, causing it to fire again. Dowdle was sentenced to probation, but his concealed handgun permit remained active until it expired in 2009.

Dowdle, 63, said in a telephone interview that although he gave away his guns after his conviction, no one had ever done anything about his permit. He said he hadn't bought a gun with it because federal law forbade it.

Besides felons like Dowdle, The Times also found scores of people who kept their permits after convictions for violent misdemeanors. Precisely how these failures of oversight occurred is not clear. The normal protocol would be for the local sheriff's office to suspend and eventually revoke a permit after a holder is arrested and convicted of a disqualifying crime, the authorities said. The State Bureau of Investigation, which maintains a computerized database of permits, also tries to notify individual sheriffs when it discovers that a holder has been arrested for a serious crime, according to a spokeswoman, but the process is not formalized.