"Right now in the drawer right next to where I'm sitting I have that Smith & Wesson Airweight," Richard Feldman, a gun lobbyist, told me the afternoon I spoke to him this summer.

Feldman, a former NRA operative who'd broken with the association over its tactics, said he keeps the small revolver handy in case someone drops by his New Hampshire home with malice aforethought. "If someone drives up and I'm not expecting tem, I don’t go out with my dick in my hand," he said.

The Airweight was Feldman's first gun. He now has 140 firearms. And, he noted, they are all safe and secure in the possession of a responsible gun owner.

"Of course," he added as an aside, "I could be loony tunes tomorrow."

The shooting tragedy in Newtown has focused new attention on the issue of mental illness and guns because Adam Lanza, the killer, suffered from some psychological disorder—although it's unclear exactly what diagnosis applied to his condition.

The same was true in 2005 after the Virginia Tech massacre; the shooter there, Seung-Hui Cho, suffered from mental problems.

In response, Congress imposed financial carrots and sticks to get states to do a better job of reporting the names of people deemed mentally deficient to the National Instant Check System (NICS), the computerized background-check tool that federally licensed gun dealers must use for every sale. But gun control groups say those measures have not proved adequate.

Layers of laws

Federal law says it's illegal to sell a gun or ammunition to someone who “has been adjudicated as a mental defective or has been committed to any mental institution.” According to the FBI, of the 976,000 people denied the right to purchase firearms through the NICS from 1998 through the end of November 2012, some 9,700—or 1 percent—were denied because of their mental health status.

But a report this summer found that 2 million people who ought to be on the federal no-gun list aren’t because of poor reporting by states.

But the NICS is only one layer of gun regulation. States have a huge hand in restricting access to firearms—and according to the National Council of State Legislatures, states display very different approaches to mental illness.

New York state's law is that "No license shall be issued or renewed except for an applicant … who has stated whether he or she has ever suffered any mental illness or been confined to any hospital or institution, public or private, for mental illness." It also stipulates that "the records of the appropriate office of the department of mental hygiene concerning previous or present mental illness of the applicant shall be available   for inspection by the investigating officer of the police authority."

New York is a "may issue" state, meaning government has discretion to decide whether someone gets to buy a gun. This authority is actually devolved to the counties.

Inside New York City, people are required to get a permit for register long-guns as well as handguns. The application for rifle or shotgun permits asks, "Have you ever been confined to an institution or treated as an outpatient for drug addiction, alcoholism or mental illness?" and requires applicants to consent to the release of their mental health records.

The handgun application asks if the applicant has "suffered from mental illness, or due to mental illness received treatment, been admitted to a hospital or institution, or taken medication?" and requires that he or she list the name and contact information for the doctor who treated them.

But outside of New York City, New York counties typically don't require permits or registration for long guns—meaning rifles (including the kind of modern sporting rifles/assault weapons at the center of concern since Newtown) and shotguns.

A flawed system

"Our permitting system is among one of the better ones in the nation," says Jackie Hilly, the executive director of New Yorkers Against Gun Violence (NYAGV).

The federal system, for instance, sets the bar for denial at being adjudicated mentally incompetent, which covers conditions so serious a person was committed to an institution involuntarily. New York has a "good moral character" clause that allows cops to identify mental issues more broadly. "We are permitted under our law to be able to examine the whole person," Hilly says.

But the state's system isn't perfect, she adds. Her organization supports not only the Fix Gun Checks Act" that would require an NCIS background check for all gun sales—even person-to-person sales that are now exempted, crackdown on states that weren't providing good data to the FBI system and refine the categories of people who are barred from buying guns.

NYAGV is also pushing a "universal background check" law for New York State to end the lack of oversight on long-gun sales. While handguns dominate gun crime in New York City, it's a different story upstate. Long-guns were recovered in only 18 percent of crimes in the five boroughs but were found in 47 percent of crimes in Buffalo in 2009.

Even limits have limits

Amid all the concern over mental illness and guns, some have warned against excesses. Most mentally ill people aren't dangerous.

And as Feldman's good-natured quip about going nuts suggests, people's mental health status can change (although it's not usually overnight).

Perhaps to account for that possibility, the NYPD's handgun permit process requires the applicant to designate someone to take charge of their guns if the permit holder dies or becomes "incapacitated."

In the Newtown horror, of course, the person who took charge of lawful firearms owner Nancy Lanza's guns when she died was her killer and son.