Esdras Mazariegos, 28, is an acquaintance of the girl's family, Sgt. Keith Heiden said. A $500,000 warrant for his arrest has been issued. The molestation was reported to police on June 1.
Mazariegos is Hispanic, 5 feet 4 inches, 130 pounds and has black hair and brown eyes, Heiden said.
Anyone with information is asked to call police at (415) 897-1122.