As a young man with a degree from Cornell, he found success as a chemical engineer at Goodyear Tire and Rubber and then at Kraft General Foods. An MBA from Columbia followed, and Smith realized he could make more money on Wall Street. After what he described as more than 100 interviews with banks, he joined Goldman Sachs in 1994 in mergers and acquisitions. Goldman later moved him from New York to be a technology investment banker in Silicon Valley. His star was rising at Goldman when he began working with Brockman, a Goldman client and code-writing whiz.

Brockman, a former Marine and IBM salesman, started his own software company in 1970 and ultimately gobbled up several other companies. Though the Texan generally shuns the spotlight, he’s also a philanthropist, creating a scholarship program at Texas A&M and serving on the board of the Baylor College of Medicine.

He decided to make a Texas-size bet on Smith, helping to lure the investment banker out of Goldman Sachs in his late 30s. Smith set up Vista with two partners in San Francisco.

Its first fund, Vista Equity Fund II, had a single limited partner, Point Investments, a British Virgin Islands entity, which made the $1 billion commitment in 2000, a person familiar with the matter said. Point Investments was held as part of the A. Eugene Brockman Charitable Trust, named for Brockman’s late father, according to Bermudian court records.

The ownership of the trust was complex, but Brockman is identified in U.K. court records as a beneficiary. The arrangement is typical of those used to help rich Americans lower their taxes. It was owned by another offshore entity, the St. John’s Trust Company, which is at the heart of the U.S. investigation, Bermudian court records indicate.

Over time, Smith, Vista and Brockman grew more intertwined. In 2006, the company that Brockman had founded 36 years earlier launched a buyout of a larger rival, Reynolds and Reynolds. Equity financing was provided by Goldman Sachs’s private equity arm, GS Capital Partners; Smith’s Vista Equity Fund II; and another Brockman trust called Spanish Steps. Prosecutors have studied that transaction, according to a person familiar with the matter.

Back at Vista, Smith racked up an astounding winning streak. In all, he’s completed more than $120 billion in deals and produced some of the highest returns in the industry over the last two decades. Vista has started a score of private equity, debt and hedge funds. Its clients include big investors like the state pension funds in New York and Illinois and the City of Los Angeles.

Life grew more complicated for Smith in 2013 when his wife filed for divorce, citing adultery. Jamaican-born Suzanne McFayden had met Smith while studying French literature at Cornell. They married in 1988 and had three children.

Experts on both sides of the divorce pored over the family finances. In 2014, Smith approached the IRS seeking amnesty from prosecution under a program used by more than 56,000 Americans who failed to report offshore assets, according to two of the people familiar with the matter. Through the program, the IRS collected more than $11 billion in back taxes, fines and penalties, while learning who enabled offshore tax evaders.

But the IRS rejected Smith, according to people familiar with the matter. The agency typically turned down taxpayers if it already knew they had undeclared offshore accounts.