Fairfield police say that witnesses reported a 17-year-old boy assaulting his girlfriend Saturday.
Investigators say passers-by saw the two in a car on Mill Pond Road and witnessed the boy punch and choke the girl. Officials say the girl lost consciousness for a short period of time.
The boy is facing charges including assault and strangulation, and is being held on $5,000 bond.
Officials say the girl was not seriously hurt.