TUCSON, Ariz. (AP) — A Tucson police officer has been fired after he was accused of shooting a shoplifting suspect in a wheelchair nine times, killing him, after the man brandished a knife, authorities said Tuesday.

Police announced at a news conference that Officer Ryan Remington was being terminated for excessive use of force.

Authorities said Richard Lee Richards, 61, died at the scene, and the shooting was recorded on Remington’s body camera.

Tucson Police Chief Chris Magnus said he was “deeply disturbed and troubled” by Remington’s actions and the case is under review by the Pima County Attorney’s Office.

“His use of deadly force in this incident is a clear violation of department policy and directly contradicts multiple aspects of our use of force and training,” Magnus said.

Tucson Mayor Regina Romero said in a statement that Remington’s actions were “unconscionable and indefensible,” and the County Attorney’s Office has her full support as it proceeds with its investigation.

Tucson attorney Mike Storie, who is representing Remington, said in a statement that his client “had no non-lethal options.”

“He did have a Taser, but in his mind, he couldn’t use it because he didn’t feel he had the proper spread to deploy it, with the wheelchair between him and Richards,” Storie said.

Magnus said Remington, a four-year veteran, was on a “special duty assignment, basically a security detail” at the Walmart store in the Midvale Park Shopping Center on Monday night.

A loss-prevention employee at Walmart told Remington a man in a motorized wheelchair allegedly stole a toolbox from the store.

According to police, Remington and the store employee followed the man outside and asked for a receipt.

Richards reportedly said “Here’s my receipt,” pulled out a knife and kept moving toward a nearby home improvement store.

Remington allegedly ordered Richards to drop the knife and not to enter the store, but the suspect ignored the officer before he was fatally shot.