Pro-gun advocates like to say that “guns don’t kill people, people do.” The policy upshot of that philosophy is to deny the agency of the gun itself in gun violence, while deflecting responsibility for gun killings to the individual perpetrator and to a myriad of other social factors from religion to mental illness.

We can enumerate a wide array of statistics to explain that proliferation of guns really is the problem. We can point out that America doesn’t have any more mentally ill than other nations with far less gun violence, that America doesn’t have a greater percentage of impoverished and poorly integrated minorities than other similar nations. We can note that Americans are far more religious than other countries with far less gun violence, so lack of obedience to and faith in God isn’t the answer. We can observe that other nations like Australia have successfully quelled gun violence with strict gun control policies.

But ultimately the human brain responds better to simple examples than to a series of statistics and imperfect correlations.

The simple truth is that the same terrorist impulse is far less deadly when guns are less accessible. Yesterday an ISIS-inspired terrorist in London shouted about revenge for Syria and tried to go on a murder spree. But the death toll was zero–not because of a lack of motivation, but because the perpetrator wasn’t able to gain access to a firearm.

Similarly, on the same day that the Sandy Hook gun massacre claimed the lives of 28 people in addition to the many wounded, a disturbed individual in China went on a knife spree at a school in Chenpeng Village, using his weapon on 24 people. Very similar incidents halfway across the world. The difference? The American had a gun and killed 28. The Chinese man had a knife and killed none of his victims because he had no access to a firearm.

Gun proponents will claim that this argument is fallacious because criminals will have access to firearms regardless. But this simply isn’t true, and the extension of that argument would be to repeal all laws entirely because criminals don’t follow them. As we all know, not even laws against murder prevent the most enraged or dedicated person from perpetrating the crime–but they do serve as a powerful deterrent for people who might otherwise engage in a casual killing. Anti-drug laws may indeed be counterproductive, but there’s no question that making it harder to legally access drugs does reduce demand somewhat (for what it’s worth.) The dedicated, well-trained terrorists in Paris were determined to smuggle guns into France using the inside compartments of cars–a level of determination that we may well not be able to prevent from time to time.

But what strong gun control laws do accomplish is stopping the casual homegrown would-be terrorist without connections and training from doing as much harm. The individuals in San Bernardino didn’t have significant training: they were simply able to buy their massive stockpiles of guns and ammunition legally online. Without that ease of access, they would likely have been either stymied entirely, or rendered as comparatively ineffective as the the knife terrorist in London. Without easy access to legal guns, Adam Lanza’s spree at Sandy Hook might still have happened, but it would have left far fewer dead as in the case of the Chinese knife-wielder.

Like locked doors, laws aren’t about preventing the hardest, most dedicated criminals. All we can do in those cases is use targeted intelligence, and in the worst case scenario catch and punish them. Laws are mostly about stopping casual crimes of opportunity.

More effective gun control wouldn’t stop all the gun deaths. But it would stop most of them. Because it’s not just people who kill people. The gun allows them to kill many, many more than they would have otherwise.

David Atkins

Follow David on Twitter @DavidOAtkins. David Atkins is a writer, activist and research professional living in Santa Barbara. He is a contributor to the Washington Monthly's Political Animal and president of The Pollux Group, a qualitative research firm.