Updated

A California man is facing as many as 13 years in prison for scribbling a series of anti-bank messages in washable chalk on city sidewalks.

40-year-old Jeff Rogers has been charged with 13 counts of vandalism for writing the series of protest slogans between February and August 2012 on sidewalks in front of Bank of America branches in San Diego. He is standing trial this week.

The city attorney brought the case to trial despite many decrying the charges, including the city's own Mayor Bob Filner.

"This young man is being persecuted for thirteen counts of vandalism stemming from an expression of political protest that involved washable children's chalk on a city sidewalk,'' Filner said last week in a memo to the San Diego City Council, according to Reuters.

Olson, who has no criminal record, tells 10 News he believes the charges against him are politically motivated. He says he wrote nothing profane on the sidewalks, and only wanted to encourage people to use credit unions.

"I think this is really heavy handed," Olson said. "I hope that (City Attorney) Jan Goldsmith reviews the First Amendment of the Constitution and remembers that free speech is protected; just because you don't like what it says, doesn't mean you can't do it."

10 News reports Judge Howard Shore has barred Olson from invoking freedom of speech as a defense in the case.

In a memo released to multiple news outlets on the case, Goldsmith defended his pursuit of the charges against Olson and denied they were politically motivated.

"We prosecute vandalism and theft cases regardless of who the perpetrator or victim might be," he said.

On Thursday, Darrell Freeman, Vice President of Corporate Security for Bank of America told the jury he believed Bank of America's reputation has suffered because of the messages, 10 News reports. Olson has claimed Freeman pressured the city attorney to bring the case to trial.

Olson is charged with 13 misdemeanor counts of vandalism, each carrying a maximum penalty of one year in jail and a $1,000 fine, though he is not expected to receive as harsh a sentence as 13 consecutive years behind bars if found guilty.

The mayor's office has not ruled out that Filner may appear as a witness for Olson, Reuters reports.

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Reuters contributed to this report