A police officer captured in photos smacking a handcuffed woman in the head at a street celebration after an Edmonton Oilers playoff game last spring should not be charged with assault, a prosecutor recommended Wednesday.

Calgary chief Crown prosecutor Gordon Wong said the Edmonton officer had little choice but to administer what is known as a "head stun" on Kristin Wilson during crowd control on Whyte Avenue on June 17.

According to witnesses, Wilson was being verbally abusive and resisting arrest on a raucous night that saw police eventually arrest close to 400 people, Wong said.

If police hadn't subdued her, they would have had to chase her, and that could have touched off a powder keg, the prosecutor suggested.

"The resulting risk of danger and the possibility that this could spark a riot meant that the police had to establish control over the complainant," Wong said in a news release.

Photos of the attack, which were shot and published by a newspaper, depict an approved takedown method, he said.

"The photographs show the officer administering a police technique known as a head stun. Officers receive training in this technique as a method of subduing someone who is actively resisting police."

The Edmonton Police Service has not commented on the case except to say none of the officers involved has been removed from duty.

Wilson, 20, of Vernon, B.C., is suing the police officer, the police service and police Chief Mike Boyd. She could not be reached immediately for comment.

In her statement of claim, Wilson alleges Const. Shane Connor struck her in the face in an unprovoked attack while she was handcuffed, causing her to fall face first into an asphalt curb.

She says she suffered a concussion, broken teeth, back trouble and psychological problems as a result. The allegations have not been proven in court.