A US police officer has been fired after fatally shooting a man in a motorised wheelchair while responding to a reported shoplifting.
Tucson police officer Ryan Remington fired nine shots at 61-year-old Richard Lee Richards during the incident.
The Arizona city's police chief said on Tuesday that he's "deeply disturbed and troubled" by the officer's actions during the incident.
Mr Remington's attorney has defended his client's actions.
On Tuesday, police in Tucson released footage of the Monday incident, which began after Mr Richards was accused of stealing a toolbox from a local Walmart.
Both a Walmart employee who confronted him and Mr Remington reported that Mr Richards had brandished a knife during the incident, refused to comply with orders to surrender the weapon, and attempted to move away.
According to the Walmart employee, Mr Richards said that "if you want me to put down the knife, you're going to have to shoot me".
The footage - drawn from CCTV cameras and police bodycams, including one on Mr Remington - shows Mr Remington and another officer following Mr Richards to the entrance of another nearby store, with one officer instructing him to "not go into the store".
Mr Remington then fires nine shots from his gun at Mr Richards, who slumps forward and falls from his wheelchair. He was then handcuffed. He was later declared dead.
"His [Mr Remington's] deadly use of force in this incident is a clear violation of department policy and directly contradicts multiple aspects of our use of force and training," Tucson police chief Chris Magnus said on Tuesday.
"As a result, the department moved earlier today to terminate Officer Remington," he added.
Tucson Mayor Regina Romero said in a statement that Mr Remington's actions were "unconscionable and indefensible".
The incident is now being reviewed by the Pima County Attorney's Office.
Michael Storie, an attorney representing Mr Remington, told the BBC in an interview that the department's overview of the case is "only half the story" and that "many more important details were withheld" from the department's news conference.
"Officers always have alternative actions that can be second guessed," Mr Storie said. "However, just because there are multiple actions, doesn't mean the one he chose was inappropriate."
An additional statement on behalf of Mr Remington is expected later Wednesday.