SAN FRANCISCO (AP) — Federal prosecutors charged Texas billionaire Robert Brockman on Thursday with a $2 billion tax fraud scheme in what they say is the largest such case against an American.

Department of Justice officials said at a news conference in San Francisco that Brockman, 79, hid the money over 20 years through complicated schemes including filing false returns and setting up secret accounts all over the world to hide and launder money. They also charged him with investor fraud.

Prosecutors also announced that Robert Smith, founder and chairman of investment firm Vista Equity Partners, will cooperate in the investigation and pay $139 million to settle a tax probe.

“Complexity will not hide crime from law enforcement. Sophistication is not a defense to federal criminal charges,” said David L. Anderson, U.S. attorney for the Northern District of California.

“We will not hesitate to prosecute the smartest guys in the room,” he said.

Brockman is CEO of Reynolds and Reynolds Co. of Dayton, Ohio.

The indictment was unsealed Thursday and Brockman is scheduled to make an appearance in San Francisco.