SAN MARINO >> A stinky video dispute between a resident and the mayor over a discarded bag of dog poop got messier Tuesday when the resident threatened to sue the politician and the city for harassment.

Resident Philip Lao said a handwritten letter of apology from Mayor Dennis Kneier, who acknowledged flinging the dog poop, wasn’t satisfying and said his next step may involve hiring an attorney.

The two have clashed over plans for a dog playground to be built at Lacy Park, which is near Lao’s home. In 2008 Kneier was the only person on the Council who voted in favor of a dog park. A new proposal was brought to the Recreation Commission on June 2, and Lao has been collecting opposition signatures. Neither man owns a dog.

“(Kneier’s) letter of apology is compounding the situation for lying about where he got it,” Lao said. “I don’t care where it was — if it fell from heaven and he got it. Chances are he had picked it up from the park. There is a dog waste station about 20 feet into the park. … That would be logical because there are lots of bags of dog poop. He brought it all the way and dropped it on our property.”

Lao installed video cameras outside his home because dogs have been pooping on his lawn. Complementing the cameras are a pair of signs that declare Lao’s property a “no poop zone.” Kneier has tried to get the city to force Lao to get rid of these signs, Lao said.

On Saturday one of Lao’s cameras captured images of Kneier and his wife on a stroll through the neighborhood. Shortly after the woman points to a spot on Lao’s walkway, Kneier can be seen tossing a plastic bag at the location.

Lao reported the act to San Marino police officials. In a press release issued Monday, authorities said Lao declined to ask for a criminal investigation.

In a letter to Lao, Kneier said he and his wife were returning from a walk at Lacy Park and found dog waste near a lamppost in Lao’s west parkway. He apologized for his mistake and said it won’t happen again.

Kneier sought to clarify some of the circumstances surrounding the incident on Tuesday.

“When I wrote the letter, I thought it was right there, but I didn’t go and check,” he said. “If I was incorrect by a little distance, then I was incorrect.”

A couple San Marino residents have written to the city to express disapproval. Nathan Ong called the mayor a bully, a vandal and “unfit for service.” He even asked that the mayor be dismissed from serving on the City Council.

“Taking differences of opinions to this level for a public, elected official is not only out of character, it’s unlawful,” Ong wrote in an email. “It violates littering ordinance, vandalism penal code, and is unbecoming of someone who is elected to represent the people.”

Resident John Barger seemed to agree.

“Retaliation to opposition to public propositions? Absolutely unacceptable and scary,” Barger wrote in an email.

If Kneier could re-do Saturday, he said he would either have left the dog waste on the sidewalk or, more likely, he would have carried the bag another two blocks to dispose of it at his home.

“I respect everybody having a position, and to try to say this is a retaliation for (Lao’s) issue on any particular thing or series of things — that I take offense to because people can have their own opinions.”