The way Vernon Jackson later recounted the story, the F.B.I. agents who stopped him along the walking path that morning assured him that they knew he was a solid citizen and said they were just after Jefferson. Always confident in his charm, Jackson invited the agents back to his home. By around 10 that morning, several carloads of investigators had converged at the house, where they carted away Jackson’s laptop computer, phone bills, bank records, and company documents.

Later that day, after four hours of interrogation, Jackson went to see his company’s attorney, David Harper. “Jeff ’s in trouble,” he told the lawyer. To Harper, Jackson seemed more surprised than worried. He didn’t yet understand that he was a target.

Vernon Jackson is now serving a seven-year, three-month sentence at a minimum-security prison in Morgantown, West Virginia, having pleaded guilty to bribery-related charges. He’s expected to be a key prosecution witness in the trial of Congressman William Jefferson, scheduled to begin in January.

Jackson declined repeated requests for an interview. However, through a review of court documents, wiretap transcripts, internal company records, and interviews with Jackson’s professional acquaintances, family members, and friends, the story of the embattled businessman emerges. Jackson sold many people on a beguiling vision of technology that could bring broadband to the underprivileged and make millions in the process. Those who are embittered—claimants of bad debts and broken agreements—say he’s a scam artist. But his many admirers say optimism was Jackson’s fatal flaw. He never let anything slow him down—even reality.

If Jackson could think only in terms of best-case scenarios, it may be because his own life so utterly exceeded rational expectations. He was born into a large, poor family in Charlotte, North Carolina. His father was a janitor and a weekend preacher. Jackson attended segregated public schools, where he excelled, scoring extremely high on mathematical aptitude tests. “I was what they call a child prodigy for technology,” Jackson once said. He ended up in Louisville, where he worked in research and development at AT&T for two decades before striking out on his own in 1990.

At the time, the internet was still in its horse-and-buggy phase, but the problem of the future was obvious: what to do about the “last-mile” bottleneck, the copper telephone wires that still ran to every building? Jackson, working with a French engineer, devised and patented a switching system that allowed data to be transmitted over copper wires with enormous efficiency. It was as if he’d figured out a way to pump much more water through the same old narrow pipes.

At first, Jackson had trouble raising money to support his ventures. Bank officers, he complained, told him they were used to loaning money to minorities for cleaning companies, not telecommunications firms. Jackson managed to assemble some local black investors. One was Olden Lee, a retired PepsiCo executive who now serves on the board of Starbucks; another was the former N.B.A. guard Darrell Griffith, or “Dr. Dunkenstein.” Jackson used their capital to adapt his invention to then-futuristic uses such as videoconferences and telemedicine. He named his new company VideoLan Technologies, joined forces with Ted Ralston, a white venture capitalist from Ohio, and went public in August 1995 at $4 a share. Shortly afterward, the company announced a $50 million distribution deal with Samsung, and the stock took off, reaching a high of more than $47. In terms of percentage gain, it was the most successful I.P.O. of 1995, a year in which companies like Netscape, Pixar, and EchoStar also went public. At its height, VideoLan employed around 30 people, including engineering and sales staff, though like many startups, it operated at a loss.

On paper, Vernon Jackson was worth around $26 million, and he lived like it, wagering serious money at racetracks and riverboat casinos. He began constructing an enormous house overlooking the ninth fairway of an Arnold Palmer-designed golf course. Meanwhile, VideoLan was falling apart. There were delays in developing software and security features that would allow the system to move from its prototype stage to mass production, and Samsung said its price was too high. Amid complaints about Jackson’s management, Ralston, VideoLan’s biggest shareholder, brought in a new group of executives, who were also white. The internal tension took on a palpable racial subtext. In November 1995, even as the stock price was rising, Jackson allegedly changed the locks to the company lab so that only he and the engineers could enter. After production delays continued, Samsung backed out of its deal, and VideoLan’s stock price began to collapse in January 1996. Jackson’s half-constructed trophy home stood roofless and derelict. Eventually a court ordered the property sold at auction, and the structure was bulldozed.