LOS ANGELES — Robert Rizzo, the former city administrator of Bell, Calif., accused of looting millions from city coffers, pleaded no contest to all 69 felony charges against him Thursday, prosecutors said.

On the eve of his trial, Rizzo made a surprise appearance in a Los Angeles courtroom and pleaded no contest to all charges, including misappropriating public funds, hiding and falsifying records, perjury and other crimes.

Judge Kathleen Kennedy indicated Rizzo would be sentenced to 10 to 12 years in prison, which would be the longest sentence in a Los Angeles County public-corruption case since at least 2001, according to the district attorney’s office.

His attorney said Rizzo would also likely be required to pay between $1 million and $3.2 million in restitution to the city.

Save 75% on a Digital Subscription Today

“Although we were prepared to go to trial and felt confident we could convict Mr. Rizzo of all charges, we are pleased he chose to admit his guilt and accept full responsibility for the irreparable harm he caused the people of Bell,” said Jackie Lacey, the district attorney.

Often grimacing at photographers who followed him and — at least until now — publicly unrepentant, Rizzo, 59, became a symbol of municipal corruption after the Los Angeles Times reported in 2010 that he was paid a base salary of nearly $800,000 a year for managing the small working-class city just south of Los Angeles, where a quarter of the residents live below the federal poverty line. Rizzo’s benefits package boosted his compensation to $1.5 million a year.

Other city officials were paid huge sums; Rizzo’s assistant, Angela Spaccia, made $376,288 a year. Five former City Council members, who were paid as much as $100,000 annually for part-time work, were convicted on corruption charges this year.

But they pointed to Rizzo as the mastermind of the scheme to enrich themselves on Bell tax dollars. Rizzo, who once owned a ranch in Auburn, had been scheduled to stand trial, along with Spaccia, next week.

Rizzo and his lawyer had previously maintained that although his salary was high, he had broken no laws.

“Today was the first step toward Mr. Rizzo’s effort to accept responsibility and put his legal troubles behind him,” said James Spertus, his lawyer.

Rizzo will still face federal charges, Spertus said, which he expected to be filed in the coming weeks. He said Rizzo would now cooperate in the case against Spaccia.

The surprise no-contest plea was a bittersweet ending for Bell residents, who had hoped a trial would reveal more details of what went on during Rizzo’s 17-year tenure.

Material from the Los Angeles Times is included in this report.