Atlanta: An Atlanta police officer has been fired for using a stun gun on a woman and punching her in the face in front of her traumatised four-year-old daughter.

Atlanta police say they found Sgt. James Hines' use of force was unnecessary.

An incident report says Hines was patrolling behind an apartment building when he encountered Maggie Thomas, who was sitting in a car with her daughter. She had an outstanding warrant for failing to appear in court for a speeding ticket.

Thomas says she was holding her daughter when she was first shocked. She dialed 911 and alerted neighbours by using her head to honk the horn. Witnesses recorded the arrest. The girl can be heard screaming, "Are you going to jail?"

Thomas' disorderly conduct charge was dropped on Monday.