In 2009, Jack Dorsey, Jim McKelvey, and Tristan O'Tierney set out with the bold goal to enable anyone, anywhere to accept credit card payments. Four years later, Square is one of Silicon Valley's hottest companies, with an estimated worth of over $3 billion. Now, McKelvey is on a much more audacious mission: to use technology to end St. Louis's history of violent crime.

St. Louis is, in fact, one of the most dangerous cities in the United States, with a yearly rate of 35.3 homicides for every 100,000 people. That number was just another statistic to McKelvey, who's from St. Louis, until it hit home last year. In May 2012, his friend's son, 22-year-old Danill Maksimenko, was shot and killed while delivering a pizza in North St. Louis. The only thing he was robbed of was the pizza itself.

"The question is, why would someone shoot another person for a pizza?" McKelvey asked me on a recent visit to Inc.'s Manhattan office, before answering that question, himself. "The only reason could be that you don't believe you have any opportunity elsewhere."

Creating Opportunities

McKelvey, who runs a glassblowing studio on the border of North St. Louis, wanted to bring that opportunity where it's most needed. So he developed a program called LaunchCode. Starting Tuesday, LaunchCode will begin placing 100 amateur programmers at 100 companies in St. Louis, including Mastercard, Build-A-Bear, Enterprise, and Monsanto. These beginners will be matched with 100 experienced programmers and work alongside them for three months, until they're ready for a full-time job. It's a small start, McKelvey admits, to solving a massive problem, but he says he wanted to prove the model works before scaling it.

"What I'm hoping is when we're on round three or four, once we really know what we can do, we can go down to the schools and say, 'If you achieve this level of mastery, we can place you in these companies,'" McKelvey says. "It'd be improper to promise such a big opportunity until I can prove it's real."

Why He Thinks It Will Work

The inspiration for LaunchCode's pair-programming initiative actually originated at Square. Since the company's earliest days, Square's developers have been working in twos, sharing one monitor for every two keyboards. "By working together, people make fewer mistakes," McKelvey says. What's more, this experience has shown that when junior programmers work with senior programmers, the newbies come up to speed more quickly. "If we can take this side effect we noticed at Square and get it to work on a regionwide basis, we can solve the talent problem in our city."

According to McKelvey, there's no shortage of jobs in St. Louis, but there is a talent shortage, because even programmers who have come through a training program or learned to code online are too green to land a job.

"You can take a tremendous amount of classes, but those classes don't place you in jobs. So what's the point?" he says, explaining why he chose not to launch yet another training program. "With pairing, we get around that problem. We can short circuit the whole thing, and get people into the companies quickly."

Companies will pay these programmers $15 an hour, across the board, which McKelvey says is another strategy to motivate new employees to improve upon their skills. "It's a very low wage," he says, "but if there's a $95,000 position just two months away, are you going to work a little harder? We want these people to be motivated, so it's a filter to keep them serious and focused on getting through that training period."

But Will It Lower Crime Levels?

McKelvey expects most applicants to the program will be graduates from the local trade schools or people who have learned to code online. And while he admits that teaching people to be better coders is a curiously indirect way of attacking crime, he believes that bringing more opportunity to St. Louis residents is a start.

"I guess when your only tool is a hammer, everything looks like a nail. Maybe if I were an educator or a cop, I'd take a different approach. But what I know how to do is blow glass and code, and I'm not going to employ 1,000 people making Christmas ornaments," McKelvey explains. "I think when you bring opportunity to an area, it tends to improve situations. If you give people hope, you give them a lot."