(CN) - A Utah police officer may have used excessive force when he Tasered without warning a woman who "posed no immediate threat," causing her to fall and sustain a brain injury, the 10th Circuit ruled, rejecting the officer's claim that his actions did not clearly violate the Constitution.
Brad Cavanaugh called police in December 2006 to help him find his wife, Shannon, who allegedly stormed out of the house with a kitchen knife after a fight.
He told Woods Cross City police officer Daniel Davis that his wife had tried to put him in a closet, and that she had been drinking and had taken pain medication before she left with the knife.
When Shannon returned, the Cavanaugh's neighbor noted that Shannon was not holding a weapon.
As she approached the front door of her home, Davis "gently placed his flashlight and clipboard on the ground and followed her, no more than six feet behind," according to the ruling.
"He fumbled with his holster for a brief moment, removed his Taser, and discharged the Taser into Ms. Cavanaugh's back without warning," the ruling states. "Ms. Cavanaugh, whose feet were on the front steps of her home, went rigid, spun around, and struck her head on the concrete steps. As a result of this fall, Ms. Cavanaugh suffered a traumatic brain injury."
Shannon later pleaded guilty to domestic violence assault and intoxication.
She and her husband sued Woods Cross City and Davis, claiming the officer's use of excessive force violated Shannon's Fourth Amendment rights.
The defendants argued that they were entitled to qualified immunity, but a federal judge rejected their motion to dismiss the lawsuit.
The federal appeals court in Denver affirmed the lower court's finding that Davis should have known that he couldn't Taser a "nonviolent misdemeanant."
"A reasonable jury could conclude that Ms. Cavanaugh had no reason to suspect that she was under arrest until after she was Tasered -- Officer Davis gave her no verbal commands and she had little reason to believe that the officers were responding to a crime," Judge Paul Kelly Jr. wrote for the three-judge panel.
"Under the facts presented by the Cavanaughs, Officer Davis's actions were objectively unreasonable and violated the Fourth Amendment."
Woods Cross City might be liable, based on evidence that the city's "unwritten Taser policy was the moving force behind Officer Davis's actions," Kelly added.
The 10th Circuit upheld the federal judge's denial of summary judgment to the city and Davis.