The Pasadena Star-News reports San Marino Mayor Dennis Kneier resigned Tuesday after outcry from residents who say he smeared their image.
Kneier remains on the City Council. Councilman Eugene Sun will serve as mayor.
Kneier found the bag of dog waste June 7 and tossed it onto the walkway of political opponent Philip Lao.
Lao recognized the mayor on surveillance video and called police. Video of the incident went viral.
In his resignation letter, Kneier says his actions were inconsiderate and disrespectful and he's stepping down because the event continues to be embarrassing to him and to the city.