DALLAS, Texas — Four Texas residents have been indicted by a federal grand jury in Dallas for allegedly promoting a fraudulent tax shelter scheme that concealed more than $1.5 billion in client income and caused an estimated $200 million in federal tax losses, according to the U.S. Department of Justice.
The indictment, returned September 22, 2026, charges Duncan John MacDonald, Sarah Duren, Richard Ronald Cayce and Thomas Weickgenant with conspiracy to defraud the United States and additional federal offenses related to the alleged operation.
Federal prosecutors say the defendants marketed a trust-based tax shelter to wealthy clients, sometimes charging fees exceeding $100,000, while falsely claiming the arrangements would allow clients to defer income taxes indefinitely without giving up control of their money or assets.
The indictment also alleges that MacDonald diverted approximately $2 million in investor funds to purchase luxury items, including a Rolls-Royce Ghost and a down payment on a yacht.
Federal Prosecutors Allege $1.5 Billion in Income Was Sheltered
According to the indictment, the four defendants promoted and sold a trust arrangement designed to make clients believe they could legally avoid paying federal income taxes.
The alleged scheme involved assigning income to sham trusts while clients continued to control and benefit from the assets and income supposedly transferred.
Prosecutors say the defendants falsely represented that these arrangements would allow clients to defer paying taxes indefinitely.
The government alleges the scheme was used to shelter more than $1.5 billion in income, resulting in an estimated tax loss exceeding $200 million.
The defendants allegedly collected substantial fees for establishing and promoting the arrangements, with some clients paying more than $100,000.
Investigators also allege that certain clients were encouraged to backdate trust documents and file amended federal income tax returns seeking refunds of taxes already paid in previous years.
Tax Return Preparer Accused of Obstructing IRS Audits
Federal prosecutors allege that Thomas Weickgenant prepared false tax returns for clients participating in the trust scheme.
He is also accused of attempting to obstruct Internal Revenue Service investigations into those clients.
According to the indictment, Weickgenant instructed clients not to communicate with the IRS during audits.
In one instance, prosecutors allege he encouraged a client not to comply with a federal district court order enforcing an IRS summons.
Weickgenant faces charges related to conspiracy, preparing false tax returns and corrupt interference with the IRS.
MacDonald and Duren Accused of Concealing Millions in Tax Shelter Fees
The indictment also alleges that MacDonald and Duren, described by prosecutors as common-law spouses, attempted to evade federal income taxes on millions of dollars they received from selling the tax shelter.
According to investigators, the couple concealed MacDonald's ownership of the tax shelter business and provided false information to federal investigators.
Prosecutors allege they also filed false tax returns, used trusts to hide income and paid personal living expenses through trusts and nominee accounts held in other people's names.
Cayce, who allegedly owned the distributorship responsible for licensing the trust tax shelter, is also accused of receiving millions of dollars in fees that he failed to report on his federal income tax returns.
Prosecutors Say $2 Million in Investor Funds Went Toward Rolls-Royce and Yacht
In a separate aspect of the alleged scheme, federal prosecutors accuse MacDonald of fraudulently obtaining approximately $2 million from investors.
According to the indictment, MacDonald solicited the money by representing that it would be used to purchase shares in a business developing digital trusts to promote the tax shelter.
Instead, prosecutors allege he used the funds for personal luxury purchases, including a Rolls-Royce Ghost and a down payment on a yacht.
The indictment further alleges that MacDonald was subject to a court-ordered injunction prohibiting him from selling securities that were not registered with the Securities and Exchange Commission when he solicited the investments.
MacDonald faces additional wire fraud and financial transaction charges in connection with the alleged misuse of investor money.
Federal Charges and Potential Prison Sentences
The indictment contains 24 counts involving conspiracy, tax offenses, wire fraud and transactions involving allegedly criminal proceeds.
The Justice Department identified the following charges and statutory maximum prison sentences:
| Counts | Federal Offense | Defendants | Maximum Prison Sentence |
|---|---|---|---|
| 1 | Conspiracy to defraud the United States | MacDonald, Duren, Cayce, Weickgenant | 5 years |
| 2–6 | Aiding in the preparation of a false tax return | MacDonald, Cayce, Weickgenant | 3 years per count |
| 7 | Corrupt interference with the IRS | Weickgenant | 3 years |
| 8–10 | Tax evasion | MacDonald | 5 years per count |
| 11–13 | Tax evasion* | Duren | 5 years per count* |
| 14–15 | Tax evasion* | MacDonald, Duren | 5 years per count* |
| 16–19 | Filing a false tax return | Cayce | 3 years per count |
| 20–21 | Wire fraud | MacDonald | 20 years per count |
| 22–24 | Transactions with criminally derived property | MacDonald | 10 years per count |
The maximum sentences listed are statutory limits for individual offenses, not predictions of the sentences defendants would receive if convicted. Actual penalties would be determined by the federal court.
IRS Criminal Investigation Leading Federal Probe
The indictment was announced by U.S. Attorney Ryan R. Raybould for the Northern District of Texas and Assistant Attorney General Colin M. McDonald of the Justice Department's National Fraud Enforcement Division.
IRS Criminal Investigation is investigating the case.
The prosecution team includes Assistant U.S. Attorney Eric B. Chen of the Northern District of Texas, along with Assistant Deputy Chief William Montague and Trial Attorney Max Willner-Giwerc of the National Fraud Enforcement Division's Tax Section.
