Ken Mattson to Plead Guilty in $100M Real Estate Ponzi Scheme

Some locals were suspicious when Ken Mattson amassed more than 100 Sonoma properties over nine years to add to his $500 million real estate empire. Few could have predicted he’d end up handcuffed in an Orangetheory parking lot and accused of running a Ponzi scheme.

Yet that was the scene in May 2025. Prior to getting picked off by half-a-dozen federal agents en route to his exercise class, the Federal Bureau of Investigation had circled Mattson for months. He was the target of a class action lawsuit alleging he tricked retirees into making off-book investments into his growing real estate portfolio. The local press investigated him, and a group of neighbors formed a watchdog group to examine the dealings of his company, LeFever Mattson Property Management, which he ran with his childhood best friend Timothy LeFever.

Now, Mattson appears ready to accept his fate.

Next week, he is due in front of a federal judge in Oakland, where he is expected to plead guilty to at least one count of wire fraud, according to the Press Democrat. Prosecutors are proposing a 12-year prison sentence. He initially pleaded not guilty to nine felony counts, which include money laundering and obstructing justice. However, prosecutors appear willing to drop some of the charges in exchange for a guilty plea, and a pledge to pay full restitution to the victims of a Ponzi scheme that cheated hundreds of investors — many of them retired churchgoers — out of $100 million.

A guilty plea next week would eliminate the need for the jury trial expected to start in 2027, and mark the end of criminal prosecution in one of California’s wildest real estate flameouts.

The scheme

Hundreds of people claim to be victims of Mattson’s scheme. He allegedly tricked his neighbors, preyed upon those who he prayed alongside, and betrayed his best friend and business partner. Prosecutors say the scheme began at least in 2009 and went on for another 15 years.

He served as president of LeFever Mattson, which he ran in a 50-50 partnership with LeFever. LeFever has not faced any charges, but as part of a settlement, he agreed to pay nearly $5 million into a restitution fund for victims and not contest the investigators’ finding of a Ponzi scheme.

Using LeFever Mattson, and KS Mattson LP — a company he ran with his wife, Staci — Mattson raised money for property acquisitions through a web of limited partnerships and amassed a real estate empire valued at $500 million, the Press Democrat reported.

Mattson, who developed a reputation as a skilled financier, started pitching investors on ownership stakes in subsidiaries that owned apartment buildings, promising regular returns through rent distributions and part of the profits upon the sale of the properties as far back as 2009. The case focuses on two Riverside County apartments — the 384-unit Sienna Pointe complex, acquired in 2002, and the 120-unit Heacock Park apartments, acquired in 2013.

Mattson kept the investments off the books, meaning that those who paid into them never had a legal claim to the properties. Many of the investors were Mattson’s retired neighbors or fellow parishioners in Sonoma County who handed over large chunks of their savings.

One Sonoma couple in their 80s invested $500,000 with Mattson after he promised the investment would ensure their disabled daughter $2,500 per month for the rest of her life.

However, instead of putting their money into the properties, Mattson spent it on himself, acquiring cars, a $10 million mansion in the wealthy East Bay enclave of Piedmont and a sprawling $6 million estate in the Sonoma hills, prosecutors alleged. Prosecutors say any returns these investors received came not from rent distributions but from loans, newer investors or Mattson’s other investments.

When LeFever Mattson sold the two apartment buildings in 2021 for a combined $107 million, the company netted a total profit of about $42 million. However, Mattson never told investors about the sale, and even continued to pitch ownership stakes into the two properties after they sold.

Mattson became particularly active in Sonoma County, using a web of limited partnerships tied to his two companies to amass 116 properties worth $242 million between 2015 and 2024. Mattson kept his companies’ business dealings opaque, and the buying spree spurred investigations from the Press Democrat and a grassroots watchdog group called Wake Up Sonoma, whose sole purpose was to examine Mattson and his companies.

Overall, Mattson allegedly cheated investors out of $100 million.

The fallout

Mattson’s plan began to fray around 2019, when he allegedly realized that his own personal returns on the LeFever Mattson properties could no longer cover the money owed to the off-book investors on the Riverside County apartment deals. Mattson knew he’d have to raise money from new investors to pay the existing ones, prosecutors said.

LeFever claims he had no idea Mattson was amassing a fortune through fraudulent off-book investments. But by 2024, LeFever, caught on, alerted investors, and reported his childhood friend to the Securities and Exchange Commission and the U.S. Attorney’s office. The pair went on to sue each other.

In an open letter sent to LeFever Mattson’s investors, LeFever confronted Mattson over his scheme.

“I certainly hope that you will come clean on what you have done and make arrangements to reimburse your victims because this is the right thing to do,” LeFever wrote, according to the Press Democrat. “In the meantime, you should consider the consequences as your many lies start to unravel.”

Within weeks, the Federal Bureau of Investigations raided Mattson’s Sonoma County home and the U.S. Dept. of Justice set up a tip line focused on Mattson. Investors began suing Mattson and his companies.

LeFever and Mattson sued each other — LeFever accused Mattson of embezzling at least $75 million from their company into his own pockets, Mattson accused LeFever of sabotage and said his friend was well aware of his investment activities.

By September, LeFever Mattson and several of its limited partnerships filed for bankruptcy.

Then, in May 2025, following a grand jury indictment, federal agents intercepted Mattson en route to his exercise class. He pleaded not guilty to the nine felony counts, and posted the $4 million bail. By July, he claimed he was running out of money for his defense, and sought permission to sell three of his properties — including his Piedmont mansion and the Sonoma County estate. The courts rejected the request. A month later, Mattson was airlifted to a hospital after he wrapped his GMC pick-up truck around a tree just outside his Sonoma home, but walked away with virtually no injuries.

Mattson maintained his innocence until April earlier this year, when prosecutors presented him with the body of evidence they planned to use. He agreed to change his plea to guilty on at least one count of wire fraud, which carries a maximum of 20 years in prison.

All the while, Mattson and his wife have continued to live in their 50-acre Sonoma estate, which was owned officially by KS Mattson Partners. His victims called out the disparity as salt in the wound.

“We’re trying to keep our home, and he’s still living in a mansion that he used our money to buy,” one victim who lost hundreds of thousands of dollars told the San Francisco Chronicle.

Then, in late May, Sonoma County courts handed down an eviction notice for Mattsons. In order for the bankruptcy estate to sell the property and use the proceeds to reimburse creditors and investors, the court ordered they needed to vacate the property by June 15, when Mattson is due in front of a federal judge to finally admit his guilt.