John Thomas set up the deal the way he had arranged nearly two dozen others. A friend said he wanted to buy as many guns as he could, so Thomas got in touch with someone he knew who had guns to sell.

The three of them met in the parking lot of an LA Fitness in south suburban Lansing at noon on Aug. 6, 2014. Larry McIntosh, whom Thomas had met in his South Shore neighborhood, took two semi-automatic rifles and a shotgun from his car and put them in the buyer’s car. He handed over a plastic shopping bag with four handguns.

None of the weapons had been acquired legally — two, in fact, had been reported stolen — and none of the men was a licensed firearms dealer.

Thomas’ friend, Yousef, paid McIntosh $7,200 for the seven guns. He always paid well.

Thomas did little but watch the exchange, but he got his usual broker’s fee of $100 per gun, $700 total. It was “the most money I’ve seen or made,” he recalled — his biggest deal yet.

It was also his last.

Amid Chicago’s ongoing epidemic of gun violence — with nearly 500 people killed in shootings and more than 2,800 wounded this year through September — the availability of guns has been blamed as a root cause and become a defining political and public safety issue.

City police have seized nearly 7,000 illegal firearms so far in 2017 and federal authorities have stepped up efforts to take down dealers.

Still, it’s by no means clear that targeting those like John Thomas makes a real difference.