A jury in Los Angeles has convicted art dealer Douglas Chrismas on three counts of embezzling money from Ace Gallery, which he founded and ran for a more than a half-century. In 2013, the business filed for bankruptcy protection. Chrismas, who is 80, will be sentenced on September 9, and faces up to 15 years in federal prison.

Prosecutors detailed how Chrismas embezzled some $260,000 from Ace’s bankruptcy estate while he was acting as a trustee and custodian. The funds from the gallery were directed to his own private museum, the Ace Museum, in 2016. (That same year, Chrismas failed to make a court-ordered payment of $17.5 million to settle debts the gallery had with artists and collectors.)

According to the Los Angeles Times, assistant United States attorney Valerie Makarewicz told the jury that Chrismas had “Champagne wishes and caviar dreams.”

Chrismas founded Ace in 1961 in Vancouver, when he was just 17, and expanded to Los Angeles in 1966. He worked with trailblazers of the California art scene at the time, like Ed Ruscha, Bruce Nauman, Sam Francis, Robert Irwin, and Michael Heizer, among others. The gallery would eventually become one of Los Angeles’s few blue-chip galleries, while New York remained the center of the commercial art world.

While this is Chrismas’s first criminal conviction, he has previously faced claims of questionable business practices, like selling work he did not own, mismanaging his gallery’s revenue, selling forged or illicitly acquired artworks, and neglecting to pay artists. He has consistently denied any wrongdoing.

In the 1970s, Irwin claimed, Chrismas failed to pay rent on a studio space that he leased to him in Venice, California, to use as a gallery. The artist said in a 2013 oral history of his life, “He never paid me a cent. I finally had to foreclose on him at the end of three years.”

Donald Judd took out an ad in Artforum in the 1980s to accuse Chrismas of selling re-fabricated versions of his work. And in 1986, the dealer spent three days in jail after being arrested on grand theft charges, when the Canadian collector Frederick Stimpson accused Chrismas of losing $1.2 million of artwork he bought from Chrismas.

In 2006, Jannis Kounellis sued Chrismas, accusing him of pocketing the profits on work by Kounellis that he had sold on consignment. The case was settled between the artist and dealer out of court.