Gun enthusiast will argue that guns are not just for killing. They can be collected, used for target practice, hunting and self-defense — although the latter two may include killing as well. However, all can agree that guns make killing easy. In fact, killing is so easy with a gun it is the weapon of choice for criminals and killers.

Where do criminals get guns?

Privately owned firearms are stolen in America between 300,000 and 600,000 times per year, according to researchers at Harvard and Northeastern universities, reported The Guardian. On the high end, that is more than 1,600 guns stolen every day, more than one every minute.

When a gun is stolen from a car, truck or home, it doesn’t just disappear. According to a 2012 Bureau of Alcohol, Tobacco, Firearms and Explosives report, Firearms Reported Lost or Stolen, lost and stolen guns posed a “substantial threat” to public safety and to law enforcement. The report suggested, “Those that steal firearms commit violent crimes with stolen guns, transfer stolen firearms to others who commit crimes, and create an unregulated secondary market for firearms.”

Americans own an estimated 265 million guns, more than one gun for every American adult. The new Harvard and Northeastern universities’ survey estimates that 133 million of these guns are concentrated in the hands of just 3 percent of American adults — a group of super-owners, reported The Trace.

The survey also found a sharp cultural shift in American gun ownership. Twenty years ago, the primary reason people listed for keeping a gun at home was recreation. Today, the primary purpose for ownership is protection.

“When I look at our survey, what I see is a population that is living in fear,” Deb Azrael, a researcher at the Harvard School of Public Health and one of the lead authors of the study, told the Washington Post. “They are buying handguns to protect themselves against bad guys, they store their guns ready-to-use because of bad guys, and they believe that their guns make them safer.”

Interestingly, surveys of gun ownership in America continue to find the percentage of Americans who own guns decreasing, even as Americans buy more guns. The downward trend in gun ownership is consistent across national polls.

The percentage of American households owning guns is at a near 40-year low in the latest CBS News poll released this summer, even though gun purchases are at historic highs. According to CBS, their survey included 1,001 Americans in the aftermath of the Orlando nightclub shooting, 36 percent of U.S. adults either own a firearm personally or live with someone who does. That’s the lowest rate of gun ownership in CBS polls going back to 1978.

So how do you keep guns out of the hands of criminals amid this odd phenomenon of gun ownership? GOP presidential candidate Donald Trump has an idea. He has proposed a nationwide stop-and-frisk policy, reported Time Magazine.

At a town hall meeting this week, Trump said the policy “worked incredibly well” in New York City, arguing that it is “proactive” and should be expanded across the country.

Stop-and-frisk is a controversial program that allows police to stop a person on the street based on suspicion of criminal activity and to frisk the person in search of a weapon. Several years ago, The New York Times reported, that federal Judge Shira A. Scheindlin wrote in an opinion calling for the end of stop-and-frisk in New York City that it had led police officers to stop “blacks and Hispanics who would not have been stopped if they were white.”

Not to mention that Trump’s “initiative” is normally a local issue implemented by municipal or state authorities. It is doubtful that a president could impose a nationwide stop-and-frisk initiative, nor should he or she advocate for such a policy.

— Matthew T. Mangino is of counsel with Luxenberg, Garbett, Kelly & George P.C. His book, “The Executioner’s Toll, 2010,” was recently released by McFarland Publishing. You can reach him at mattmangino.com and follow him on Twitter at @MatthewTMangino.