Chicago is a major trafficking route for Mexican cartels and has become a hub for the distribution of heroin across the Midwest. The dangerous result has been an increase in heroin overdose deaths in Illinois.

That has WBEZ and the Chicago Reader digging into how so much heroin gets here, how it’s distributed and who gets hurt. Those stories will unfold over the next two weeks.

But let’s begin with some background:

Heroin is purer, the street price has significantly dropped and the growing cohort of users is white suburban young people.

Jack Riley is the no-nonsense agent who runs the Chicago division of the U.S. Drug Enforcement Administration. He’s made it a goal to dismantle one Mexican cartel’s grip.

“It’s really clear to us that Sinaloa really controls 70-80 percent of the narcotics in and out of Chicago and thus the Midwest,” Riley said.

By the numbers

• Heroin seizures in the Chicago area
• Heroin-related ER visits by city
• U.S. retail price of heroin

The leader of the Sinaloa cartel is El Chapo Guzman. He’s considered the world’s most powerful drug trafficker and is designated “Public Enemy Number 1” in Chicago. And, by the way, Riley says Guzman once put a bounty on his head.

“Chapo Guzman is a logistical genius. He’s been on top of the game for 25 years. He has an unlimited amount of revenue. He has the ability to corrupt, obviously to kill. And I think he’s relentless in his control of the Midwest and heroin market,” Riley said.

Riley previously worked DEA investigations in the border city of El Paso, Texas.

He said the cartel’s focus on heroin is a market decision, based on Sinaloa’s ability to produce and continue to supply the drug, with the cooperation of Colombian producers.

“If you look into Mexico, you’re seeing them really fortify their ability to produce high-quality poppies and in turn produce heroin on their own. That’s something we hadn’t seen up until the last few years. The majority of it was being produced by the Colombians. We’re seeing the migration of two producers come together to serve one market,” Riley said.

And that is contributing to the heroin problem in Chicago, its suburbs and the Midwest, because the drug is more accessible these days at cheaper prices.

The Sinaloa cartel’s impact is currently playing out in a smattering of federal court cases in Chicago.

Heroin dealing stretches throughout the Chicago region and collar counties.

However, the most visible aspect of drug trafficking is typically open-air drug markets in low-income areas of the city.

RELATED: The Chicago Reader‘s Mick Dumke on the business of drugs: The West Side’s main employer

And that face tends to be young black males on the corner. This group is also disproportionately represented in the criminal justice system.  And they’re there for narcotics violations. Open-air drug markets disrupt quality of life and often invite violence in many Chicago communities. But they are just part of the heroin story.

“There’s a lot of drug selling that occurs that isn’t open air. We don’t see that, so there’s that hidden part,” said Kathleen Kane-Willis. She is the director of the Illinois Consortium on Drug Policy at Roosevelt University—and a former heroin user.

Kane-Willis said people of all races struggle with substance abuse.

“The drug markets tend to reinforce existing beliefs about who uses and who sells drugs. So we tend to think of African-American males as users and sellers of drugs. As we start to look outside of that framework we can see that’s not the case,” she said.

Experts say the upward trend of heroin use started in 2004. In fact, Metro Chicago now leads the nation in emergency room visits for heroin overdoses. 

Kate Mahoney is the executive director of Peer Services, a suburban-focused treatment program based in Evanston. People trickle in for counseling and methadone, which treats heroin addiction, one weekday morning.

“I’m shocked that I’ve been doing this work for 30 years and in 1983 when I started working in addiction treatment, a bag of heroin cost about $50. And today in 2013, you can purchase a bag of heroin (for) between $5-10,” Mahoney said.

That makes the drug more accessible. And people don’t have to use needles anymore. Heroin can be snorted and is regarded in some circles as a recreational drug. Law enforcement officials say it arrives from Mexico 90 percent pure and is sold at a purity of nine to 12 percent on the street after being cut and pumped with additives.

Mahoney says decades ago, heroin was an end-of-the-line drug after people had been abusing 10 to 12 other drugs. But it’s not always the case.

“There’s a number of parents on the North Shore who can’t see or believe that their child has a problem. We’ve seen young people die because they don’t understand that it could be their child—who’s going to a top high school and achieving well and simultaneously looking at college applications and prepping for the ACT or SAT—might also be using heroin,” Mahoney said.

Chicago is uniquely positioned as a major heroin hub because of its centralized location and ample transportation that can help people deliver and disperse narcotics across the Midwest.

The Chicago Police Department is trying to curb the street violence that accompanies the drug trade. The police narcotics strategy is to erase open-air drug markets and turn those blocks back over to the community by coordinating city services and clean up.

But doesn’t that mean drug dealing will move to another corner?

“I don’t think that law enforcement is going to fix the narcotics problem in this country. And many people would say that’s blasphemy, but I think it’s reality,” Supt. Garry McCarthy said. “The fact is what’s our baseline issue: reducing crime and violence in the city. What I’m trying to do is stop getting people killed on the street corners in the city of Chicago.”

But as long as the demand for drugs is high, the supply will be there.

Natalie Moore is a WBEZ reporter. She can be reached at nmoore@wbez.org or on Google+ and Twitter.