Marcus Bullock was 15, in a maximum-security prison with men who had already spent decades behind bars, and he was thinking about his Christmas presents.

His girlfriend had promised to buy him a T-shirt, and he couldn’t wait to wear it to school. He also knew his mom planned to get him some new video games, and he could already picture himself playing with friends.

In the courtroom, the teenager had heard a judge sentence him to eight years, but he didn’t give that number the weight or the worry it deserved. He thought once he stepped into that cell, those years would dissolve into weeks or days. He thought he would be home in time to unwrap his gifts.

“I was in complete denial,” Bullock recalls. “I thought they’ll realize they just wanted to teach me a hard lesson and they’ll let me go. There was nothing that could convince me at that time that I was actually going to grow up in there.”

When Bullock finally walked out of prison, he was a 23-year-old man whose formal education didn’t go beyond completing ninth grade.

You might think you can guess how Bullock’s life unfolded from there. You would be wrong. Even he couldn’t predict the success he would find, and how it would place him in the unique position to talk about the power of investing in “people who seem uninvestable.”

On Wednesday, Bullock walked into a building just blocks from the White House and stood in front of a room filled with influential people. He was joined there by three other men who share his basic biography. They all are people of color, live in the D.C. area and served time in prison.

They are all also entrepreneurs who have reached dizzying heights when you consider where they started.

They came together Wednesday to talk about where they had been so they could convey where they want to go. They were there to offer pitches for expanding their businesses and to explain why an investment in them was also an investment in the public.

“There is a social mission packed into the DNA of every one of these companies,” explains Sara Gibson, the co-founder of 20 Degrees, a management consulting firm that advises nonprofits and social enterprises. As part of a pilot program offered through a D.C. grant, the company worked with the four men over the last four months to evaluate their business plans and sharpen their pitches.

Gibson says each business has the “ability to transform communities.” They all employ people with criminal records, and studies have shown the formerly incarcerated are more likely to end up back in prison when they don’t find jobs. They also serve “opportunity zones,” which the IRS defines as economically distressed communities “where new investments, under certain conditions, may be eligible for preferential tax treatment.”

“The better they do, the better our communities do, the better the District does, the better America does,” Gibson says. Or to put it more concisely: “The better these businesses do, the better we all do.”

The Wednesday event marked the culmination of the program. Among those in the audience were D.C. government officials, wealth managers, impact investors, nonprofit leaders, lawyers and bankers.

Lorenzo Stewart knows exactly what his business needs to grow: money to invest in technology.

He started transporting people with disabilities three years ago to fill a need he noticed from personal experience. At 15, he was shot during a robbery and ended up paralyzed from the waist down. From his wheelchair, he encountered elevators that were broken, cabs that wouldn’t stop for him and ride services that would tell him to call back in two hours because no one could accommodate him.

He named his company VOW, he explains, because those situations “made me take a vow to help provide services for people with disabilities.”

He now has four vans and, through different contracts, takes people to and from appointments and transports children for a private school in the District. He picks up one from New York Avenue, where homeless families are housed in hotels.

Stewart says he hopes to expand his fleet, offer drivers a chance to receive training beyond the basic requirements and create an app that would allow parents to track their children in real time while they’re in his vans.

“You can go to my app and you will see that your kid will arrive home in 10 minutes,” he says.

He’s now a 44-year-old married father of two and says he’s come far from the teenager who sold drugs for fast money and served time for it. Now, he wakes at 4 a.m. to start work and loses sleep, worrying about payroll and keeping the business profitable. He says he also believes in hiring people with criminal records because he remembers that frustration of getting temporary jobs that never turned full time.

Bullock recalls applying to 41 jobs and facing 41 rejections. He says he finally got lucky at a paint store because of a comma. Others applications had asked: “Have you ever been convicted of a felony?” The one for the paint store read: “Have you been convicted of a felony, within the last seven years?” He was able to say no.

The 38-year-old blames a “dumb decision” for landing him in the adult prison system in 1996. He and a teenage friend stole a car at gunpoint. No one got hurt, he says, but he lost eight years of his life and his friend lost nine.

At the paint store, Bullock says he distinguished himself as the top salesperson and soon went from earning $12 an hour to $85,000 a year. He then started his own business, connecting people who came in to buy paint with those who could paint for them. Eventually, his company grew into a construction business that was able to land a project with BWI airport.

“My life turned into something incredible, something I wasn’t even smart enough to pray for,” Bullock says.

The idea for his more recent company grew from an office conversation he had with the vice president of his construction business, a man he met in prison named Anthony Belton. They started talking about how they hadn’t spoken in a while to some of their friends who remained incarcerated, and the reasons for that: No one had time to write letters anymore and phone calls from prison were too expensive.

When Bullock was in jail, his mother used to send him letters filled with photographs. One picture might show a cheeseburger and come with a reminder that when he got home, he could again “enjoy a fat, juicy burger.” Or she might send a picture of a new shampoo she purchased along with a note saying he would soon be able to take a long shower, with hot or cold water.

“That was the only thing that kept me alive was my mother’s photos and letters,” Bullock recalls. “I told Tony, ‘There is an app to help me get my coffee quicker. There has to be an app that helps me connect to my friends in prison.’ ”

There wasn’t, so Bullock worked to create one. Flikshop now allows family members to upload photos with messages that are then printed out at the company’s Southeast D.C. headquarters and mailed as postcards to prisons. Bullock says the app has now connected more than 158,000 families across all 50 states.

“Here’s the thing that always gets me, every time I walk into the office: The vast majority of photos that Flikshop ships out are of children,” he says. Those photos show first days of school, Halloween costumes, Christmas mornings. “I see sonogram pictures that are coming through that say, ‘I know you just got there, but when you come home, we’ll be waiting for you.’ You look at that and you think, ‘Damn, this is what’s going to keep people out of prison.’ ”

He welcomed the chance to talk Wednesday to “a lot of people I probably would not have had the chance to get in front of.” He has spoken at the White House and to tech companies in Silicon Valley, but he says he still gets plenty of doors slammed in his face.

Standing with Stewart and the two other men — Will Avila and Maurice Dixon — shows people what he has tried to convey to other investors.

“There is no shortage of innovative ideas,” he has told them. “The reality is you guys are not investing in the communities that can come up with them.”

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