Author Stephen King once asked his publisher to pull one of his novels off the shelves.

Six people had died — in real life.

Four boys in 10 years brought guns to school. One killed a teacher and two students. Another shot five members of a prayer group, killing three. All four teenagers had read Rage, a book King wrote when he was a teen himself and published under another name.

King, in a blunt, impassioned essay, wrote that when he learned of the copycat crimes, he wanted the book off the market. He argues the United States should do the same for assault weapons.

“You don’t leave a can of gasoline where a boy with firebug tendencies can lay hands on it,” he said in the 25-page piece, published last week for Amazon Kindle readers.

King, a Democrat who says he owns three handguns and supports the Second Amendment, argues stricter gun control “would save thousands of lives.” (His earnings from the sale of the essay will go the Brady Campaign to Prevent Gun Violence.) He says Australia shows it’s possible.

In 1996, 28-year-old Martin Bryant shot and killed 35 people near Australia’s Port Arthur historic site, a popular tourist destination. After the shootings, the country banned and bought up automatic and semi-automatic long guns, destroying at least 600,000 in 12 months — ultimately about a third of its privately owned guns.

It worked, King argues.

“Since the Bryant killings and the resulting tough gun laws, homicides by firearm have declined almost 60 percent in Australia. The guns-for-everyone advocates hate that statistic, and dispute it, but as Bill Clinton likes to say, it’s not opinion. It’s arithmetic, honey.”

We wanted to know: Have homicides by firearm in Australia dropped almost 60 percent? And did those “tough gun laws” do it?

We asked King and Australian and American experts in gun violence for evidence.

By a few different measures, the arithmetic works. Homicides by firearm did decline after 1996 — in fact, had already been in decline.

One path to “almost 60 percent” comes from statistics compiled in part by Philip Alpers, a public health professor at the University of Sydney. The number of gun homicides fell from 69 in 1996 (excluding the 35 victims of the mass shooting prompting the laws) to 30 in 2012.

That’s a decrease of 56.5 percent.

(And, yes, you read those numbers right. The United States has about the same number of gun homicides every day as happened in Australia last year.)

Then there’s King’s source, an item from Slate.com, he told us. It was a blog post citing a blog post citing a study — a reputable peer-reviewed piece in the American Law and Economics Review.

The researchers, Andrew Leigh of Australian National University and Christine Neill of Wilfrid Laurier University, found that in the decade after the gun laws, firearm homicides dropped 59 percent.

So, on the numbers, King has strong support.

But did the 1996 laws drive the numbers? That’s more vexing.

“He could be right. Or he could be wrong,” said David Hemenway, director of the Harvard Injury Control Research Center, who wrote a helpful 2011 summary of the evidence. “The true answer is, we really don’t know.”

Leigh and Neill designed their study to test for the law’s effect. They asked whether death rates dropped more in states that destroyed relatively more banned weapons through gun buybacks.