Thirty-five-year-old Phillip Dominguez has been arrested for the Tuesday afternoon attack. He is expected to be arraigned Monday on charges including aggravated child molestation.
Santa Clara County prosecutors say the girl was at a neighbor's apartment when Dominguez brought her to his place in the same complex.
Prosecutor Steve Fein says Dominguez's girlfriend, 29-year-old Racquel Martinez, walked the girl back to the neighbor's home after Dominguez sexually assaulted her.
Martinez has been arrested on suspicion of aiding and abetting Dominguez in eluding capture.