The move adds to the string of bankruptcy cases now tied to Mattson, including a business he controlled with his wife, and the partnership most closely associated with his once vast Sonoma Valley real estate empire.
A month after Ken Mattson agreed to enter his company, KS Mattson Partners, into bankruptcy, the indicted Sonoma real estate investor followed along Thursday as an individual.
The separate business entity Mattson cofounded with Tim LeFever had been attempting to force that move since last November, through involuntary bankruptcy filings.
Mattson fought on behalf of himself and KS Mattson Partners, but has now relented on both fronts.
The move adds to the string of bankruptcy cases now tied to Mattson, including LeFever Mattson Inc., the partnership founded in 1999, which, until its implosion last year, had amassed a real estate portfolio valued at $400 million, much of it based in Sonoma Valley.
A U.S. Bankruptcy Court judge in the Northern District of California had already entered a preservation order May 15, requiring court approval of any sale or “financing transaction” by Mattson as an individual. When Mattson officially enters bankruptcy Sept. 2, it will lock in those provisions for an indefinite period, potentially preserving assets for the hundreds of people who claim the financial adviser defrauded them.
“The Committee believes this is a positive step in the overall process of resolving claims against LeFever Mattson and related parties,” Kevin Katari, chair of a creditors committee formed by the U.S. trustee in the separate LeFever Mattson bankruptcy case, said of Mattson’s recent decision. “Certainly many investors hope that Ken will put his assets on the table to help address the significant harms investors have experienced.”
It isn’t clear whether it will be Chapter 7 or Chapter 11 bankruptcy. The former is often referred to as liquidation, the latter as reorganization.
FBI agents arrested Mattson in Napa on May 23. Prosecutors accused him of running what they described as a “classic Ponzi scheme,” and a federal grand jury indicted him on a total of nine counts of wire fraud, money laundering and destruction of documents. He has pleaded not guilty on all counts and is free on a $4 million bond while awaiting a trial date.
Mattson is currently wrangling with federal prosecutors over finances in that criminal case, which is also being tried in the Northern District of California.
In a June 25 motion, he accused prosecutors of violating his Sixth Amendment rights by imposing harsh financial constraints that he contended make it impossible to pay his lawyers of choice. Randy Sue Pollock of Fennemore Law and William Frentzen of Morrison & Foerster have been representing Mattson on the criminal charges.
After he was arrested, Mattson said in the filing, the government attached notices of lis pendens against real estate properties he owned. Those notices inform any potential buyers the parcels may be subject to litigation.
The government also required Mattson to post one of his properties, a home at 210 La Salle Ave. in Piedmont, as bail, and marked two others — 62 Farragut Ave. in Piedmont and 1834-1836 Ocean Front in Del Mar — for potential forfeiture should Mattson be found guilty of the charges against him.
Because of these limitations, Pollock wrote in the motion, “Mr. Mattson currently has access to only nominal — and grossly insufficient — funds to support his legal defense.”
Mattson estimated the properties under the lis pendens notices are worth $21 million, while the La Salle Avenue property is worth about $4 million.
Federal prosecutors filed their response Wednesday, pushing back on every point.
They argued, for example, that Mattson should in fact have plenty of cash, or assets that could be liquidated.
They noted that his wife, Stacy, bought two new vehicles for a total of about $180,000 in September, paying cash for both. (Ken Mattson was driving one of the vehicles on the day of his arrest.)
And Mattson, either individually or through KS Mattson Partners, sold about 40 classic cars through Bonhams Auction House between August 2024 and February 2025, netting just under $3 million.
In addition, the government said, two witnesses told federal agents in June that when the Mattsons anticipated an FBI search of their home on Castle Road outside Sonoma in May 2024, they quickly sold off assets including personal luxury items and jewelry.
They were aided by one of the “sureties” in Ken Mattson’s bail agreement — those liable for potential criminal charges of their own should he abscond. That person (“SURETY 1 in the document”) also stored valuables for the Mattsons in their home, and set up a bank account in Stacy’s name so she could have money “stashed away” in case the defendant went “away forever,” according to documents filed by prosecutors.
Ken Mattson’s sureties are Stacy, her sister Jennifer McCarthy and two of the Mattsons’ children — son Alex and daughter Hannah.
Prosecutors also argued in their opposition that a lis pendens notice isn’t a pretrial restraint at all; Mattson is free to sell any of those properties if he’s able to find a buyer willing to take on the risk. And they wrote that Mattson has no ability to sell 62 Farragut or 1834-1836 Ocean Front to fund his defense, because both are partially or wholly owned by KS Mattson Partners, “an entity over which he no longer has any control.”
That’s why Magistrate Judge Alex Tse decided against posting the Castle Road property — a 50-acre lot with a 7,600 square-foot residence, valued at around $7 million — as bail, federal prosecutors said. It’s titled in the name of KS Mattson Partners.
The Pretrial Services office of the Northern District of California had advised Tse that Mattson posed a risk of flight and a danger to the community. After hearing nine wronged investors speak in his courtroom May 28, and reading written statements submitted by more than 75 of them, the judge agreed, ordering $4 million bond to mitigate flight risk as part of his release.
It was secured by 210 La Salle, a home in Reno owned by McCarthy, $100,000 in cash from McCarthy and another $100,000 from “R.L., a friend of the defendant’s,” as the government’s opposition document said.
Mattson also agreed to wear a GPS monitor, and can’t travel outside the area bounded by the Northern District of California and Solano County.
You can reach Phil Barber at 707-521-5263 or phil.barber@pressdemocrat.com. On X (Twitter) @Skinny_Post.