Ken Mattson reverses guilty plea, heads to jury trial

Ken Mattson, the embattled Sonoma investor and developer accused of defrauding investors out of $100 million in an alleged Ponzi scheme tied to a real estate empire, will plead not guilty to federal charges, a reversal of his legal strategy.

Mattson, who initially pleaded not guilty to all nine felony counts levied against him after his May 2025 arrest, was set to appear in federal court Monday to submit a guilty plea on at least one count of wire fraud. As part of the plea deal, Mattson would skip a trial and face a 12-year prison sentence, effectively ending the prosecution of one of the Bay Area’s most dramatic developer flameouts.

But it appears that Mattson has once again had a change of heart.

“This evening, defense counsel informed the government that the defendant does not intend to plead guilty on June 15, 2026, and will instead persist in his plea of not guilty,” U.S. attorney Craig Missakian wrote U.S. District Judge Jon Tigar on Thursday.

The sides will now move to set the case for a jury trial, according to Missakian’s letter.

Mattson faces nine felony charges, including seven counts of wire fraud and one count each of money laundering and obstruction of justice. Each count carries a maximum 20-year prison sentence. Mattson’s attorney, Randy Sue Pollack, did not immediately return The Real Deal’s request for comment.

Mattson was arrested by federal agents in May 2025. An investigation found that between at least 2009 and 2024, he had misled hundreds of investors into believing they were buying into properties held by his two companies, LeFever Mattson Property Management and KS Mattson LP. Between the two companies and a complex web of limited partnerships, Mattson and his business partners — who included his childhood best friend Timothy LeFever, and his wife, Staci — amassed a real estate empire at one time valued at $500 million.

On his own, Mattson allegedly used the companies to pitch investments in two Riverside County apartment complexes, promising regular returns through rent distributions and profits upon the sale of the properties. However, he kept these hundreds of investors — many of whom were his retired, churchgoing neighbors in Sonoma — off the books. Instead of buying legal ownership stakes into the properties, the money allegedly went to Mattson himself. He used the investments to acquire 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.

Mattson’s trial was initially set to begin in 2027. It’s unclear if his flip-flopping plea will impact that schedule.