A lawyer charged with helping private equity billionaire Robert F. Smith evade taxes for more than a decade died just before he was about to go on trial.

Carlos Kepke’s death over the weekend was confirmed Monday by his attorney Grant Fondo. Kepke, 83, was set to go on trial Monday in San Francisco federal court on charges of conspiring to defraud the Internal Revenue Service and aiding and abetting the filing of false tax returns by Smith, founder of Vista Equity Partners.

Lawyers for Kepke had previously raised his age and poor health in arguing for him to appear remotely for certain pre-trial proceedings. They noted that he’d had two heart attacks and a history of other cardiac ailments.

The passing of Kepke means the case will be dismissed. That relieves Smith, 59, of the need to testify as the government’s star witness. The billionaire was expected to recount how Kepke helped him evade taxes on $225 million in Vista income by setting up a trust structure with tentacles in Belize, Switzerland, Nevis and the British Virgin Islands. Under an unusual 2020 agreement, Smith avoided prosecution for tax crimes. 

A spokesman for Smith declined to comment.

This article was provided by Bloomberg News.