Video images from a surveillance camera show the boy vandalizing a commercial building. A previous photo of a vandalism suspect released in July appears to be the same boy, Lt. Greg Hurlbut said.
The graffiti occurred on the back of buildings on the west side of Interstate Highway 80, Hurlbut said.
Other images show a girl 6 or 7 years old running away with the suspect, Hurlbut said.
The photos have been sent to schools to help identify the suspect.
Anyone with information about the suspect or the graffiti in the Cordelia area is asked to call Fairfield police at (707) 428-7300 of CrimeStoppers at (707) 644-STOP.