One thing struck him as particularly odd:

" ... as I'm ringing up the transaction, he has one of those little drawstring backpacks. He pulls a paper bag out, takes out 10 grand in cash rubber-banded in thousand dollar increments. It was weird that, one, he came in with $10,000 cash. And he didn't want any ammo for it or any optics for it. He didn't know much about it beside the fact that he wanted it."

We might have chalked him up as just another Call Of Duty fan with impulse problems, but our source considered this a "red flag" for straw purchasing. A straw purchase is when someone buys a gun legally, but then hands it over illegally to another person. This is how the cartels get the vast majority of their arsenal. Eighty-seven percent of traceable firearms seized by the Mexican government have been traced back to the U.S. We've inadvertently "gifted" Mexico with more than 64,000 firearms over the last five years.

Sandy Huffaker/Getty Images News/Getty Images

Our source and his manager didn't call the authorities immediately -- buying a fancy gun with cash isn't illegal; otherwise, how would we have rap videos? But, gradually, their suspicions began to pile up ...

" ... then, we started getting more and more phone calls over the weeks. Same questions. We had four or five come in ... that first guy came in five or six times, saying he was starting a collection. You don't buy five to six of the same 10k rifle for a collection."

After a couple weeks of escalating sketchiness, they reported the straw purchasers to the ATF, who immediately showed up to shut this s**t d-

"The ATF said, 'Don't refuse 'em, just let 'em go. Do it.' And we're on commission at the time, so all of us involved are like ... sweet! It got to the point where we would give the ATF our cellphone numbers. They only wanted a couple of us dealing with it ... fill out this form, have the money counted, so we can bring drug dogs in to check the bills for drugs. There were undercover agents in the store, sometimes."

It was a good gig for a while. All the illegal purchases followed the same basic pattern, "They would always call, because they always wanted to know the exact amount ahead of time -- usually same day -- and make sure we had one in stock. Within the next 45 minutes to an hour, they would come in."

Once the purchase was completed and the "customer" left the store, " ... the money was counted with the cameras watching it. And then paperwork started."

Spencer Platt/Getty Images News/Getty Images

"Once the ATF was more involved, we had a separate set of paperwork. You took their 4473 [the form you fill out to buy a gun] and transcribed all that, then it asked what type of transaction it was, how many 100s, how many 50s, how many 10s, ones. Then, basic questions: Did you feel they knew what they were buying? Did they buy ammo? Accessories?"

Did you feel they enjoyed their purchasing experience? How could the ATF make selling firearms to the cartels a more pleasurable process? How does the cartel feel about branded accessories? Would they be interested in Hello Kitty grips or SpongeBob sights?

It costs between $8,000 and $10,000, and it can literally put a bullet through most light tanks. Today, the two primary uses of the Barrett are "anti-material" (aka destroying enemy vehicles) and "ridiculous toy for rich people." Barretts were basically the only gun the cartels wanted, and while they are both ridiculous and rich, we get the strange feeling these weren't meant as toys ...

" ... it started to get more and more severe. We were placing special orders with Barrett because we couldn't keep up [with] demand. At one point, it was probably four to five of these rifles a week. Also FN57 pistols ... but, the Barretts were the big one."

Chris Browning, Gun News Daily

The Barrett is a rifle with almost no practical criminal uses. It weighs around 30 pounds and costs as much as a damn car. The reason the cartels had use for the Barrett is chilling: When you're as large as, say, Los Zetas, your "turf wars" involve the Mexican army. A gun that can shoot through tanks is pretty useful for that. And, lucky for them, America had a surplus of Barretts, because "f**k yeah."

Other than "buying the same $10,000 gun multiple times" and "paying in whale-choking bundles of cash," there was nothing particularly shady about the dudes making these straw purchases.

"These kids weren't sketchy looking dudes; they were all clean-cut, and some were Hispanic. But, one boy was a white boy who told me he had served. We had a bunch of light machine guns, like an M249 SAW ... what caught me off guard is that he and I shot the crap about that one day. Then, he says, 'Oh, I've been interested in the Barrett.' I'm like, 'makes sense, he's a military kid.' But then, he broke out the huge bag of cash."

John Kuczala/DigitalVision/Getty Images

The cartels were smart enough to pick buyers who wouldn't instantly set off alarm bells (aka clean-cut and often white). "They didn't look like they were all connected ... One guy came in with his wife and kids. These guys aren't stupid. They know how to pull the wool over your eyes."

This made for an interesting customer service dilemma: How do you deal with a customer you know is:

1. Actively providing firearms to one of the most dangerous organizations in the world and ...
2. Being monitored by the ATF, so ...
3. They're probably gonna go to super-prison for that.

Steve Allen/Stone/Getty Images

"You put on a face, like any customer service job, and you try to build a rapport with these guys. So, you would come in, say hello, shoot the s**t, ask him about his kid. You try and keep it as normal as possible; you don't want to spook him because then everything's shot as well. Yes, it was stressful but, at the same time, you knew what you had to do, and you did it and tried not to spook him, or whatever."

So ... same basic rules as slinging coffee at Starbucks, only with slightly higher stakes if somebody doesn't buy your fake smile.

The perfect moment to strike, of course! All of the straw buyers were arrested in one fell swoop in 2011. That sounds great, but the agent working with our source and his store told everyone that the charges wouldn't stick:

"Our agent was pretty candid with us: He let us know the guys doing it had been arrested. Then, they were let go, because what they had done hadn't been illegal -- they hadn't seen a hand off. They weren't tracking them well enough; everyone made it over the border."

Sandy Huffaker/Getty Images News/Getty Images

Your elite government task force in action, everybody: "Guess we just gave the bad guys a buncha weapons." *awkward shrug*

If our source's store had just followed their guts and refused to sell to the most obviously sketchy buyers, the world would've been a little bit safer. Instead, the ATF lost 1,400 (or more!) weapons to Mexico. Two of those weapons were tracked to the murder of a U.S. Border Patrol agent:

Patty Jahner

The whole mess immediately became an embarrassment for the Obama administration. But, the ATF's "sell guns to cartels and then maybe try to catch them if we've got time" plan actually dates back to the Bush Administration. "Project Gunrunner" (at least they were honest with the name) kicked off in 2006. "Operation Wide Receiver" was a subset of the overall project, centered around Arizona. "Operation Fast And Furious," the one you've actually heard about, launched in 2009.

For our source, who did nothing but exactly what the law told him, watching the bloody aftermath of the scandal was traumatic:

"Our initial thought was how many of these can be pointed across the border at our guys? We were a large store ... you meet these border patrol agents coming to pick up extra stuff. Man, how awful am I gonna feel if one of these guys gets plugged with a weapon I sold?"

US Government

Well, worry not, James, because the victims were mostly-

"And it's not gonna feel any better if I hear about some village in Mexico getting wiped out."

Oh. Well, crap. Sorry, man -- at least 150 Mexican civilians have been hurt or killed by weapons the ATF let enter Mexico.

And how many bad guys did they get? Thirty-four. Not all of them went to prison, and none of them were cartel bigwigs. Meanwhile, check out this picture of a gun cache from El Chapo's hide-out:

ElBlogDelNarco.com

That's a Barrett .50 caliber rifle, confirmed to have gotten to Mexico via the ATF's gun-running program. Hell, our source might have sold El Chapo that very rifle.

Maybe, he'll see this and send a thank you card.

Robert Evans just wrote a book, A Brief History of Vice, where he experiments with strange ancient drugs. Pre-order it now! And follow Robert on Twitter.

Cracked is up for TWO Webby Awards, for Best Humor Site and Best Video Entertainment! While we're busy patting ourselves on the back, you can pat too by voting here and here.

For more insider perspectives, check out 5 Insane Things I Learned About Drugs As An Undercover Agent and 6 Ways Life In Cartel-Run Mexico Is Nothing Like You Imagine.

Subscribe to our YouTube channel, and check out another How To Solve The Country's Gun Problem, and watch other videos you won't see on the site!

Also, follow us on Facebook, and we'll follow you forever.

Have a story to share with Cracked? Email us here.