Racist language, the phrase "white power" and a Swastika were found spray-painted on a restroom in Blue Rock Springs Park in Vallejo on Wednesday, police said.
The Vallejo Police Department said in a statement that it is investigating the graffiti as a hate crime.
"This was an evil, despicable act and these types of crimes will not be tolerated in our community," Chief Shawny Williams said. "The dignity and worth of all people should be valued and respected, and this is the standard we must uphold."
Williams said Jimmy Jackson, president of the Vallejo chapter of the NAACP, told him that the organization stands with local police against all acts of hate.
Anyone with information about the incident is encouraged to contact the Vallejo Police Department Crime Tip Line at 1-800 488-9383 or Officer Smith with the Detective Division at 707-648-4080.
