A serving Metropolitan Police officer has been found guilty of assaulting a man he believed was the perpetrator of a crime rather than the victim.
PC Jonathan Marsh, 33, went to a report of a man making threats to kill and damaging a shop in Atlanta Boulevard, Romford, east London, in November 2022.
He mistook Rasike Attanayake, who had called 999, for the suspect, arrested him and punched him in the head.
At City of London Magistrates' Court, Marsh had denied common assault.
Mr Attanayake was arrested and later de-arrested at the scene.
Speaking outside court following the conviction, Mr Attanayake said he had been in pain during the incident and had believed he was being suffocated.
He said what had happened demonstrated a need for policing tactics around stop-and-search to be reassessed.
Marsh had denied using excessive force during the incident, after responding to reports that a man had been making threats to kill and was throwing a shopping trolley around.
The court heard that Marsh mistook Mr Attanayake for the suspect, and that he matched the description that had been given to officers.
'Not justified'
Police-worn bodycam footage played to the court showed Marsh pulling Mr Attanayake to the floor, swearing at him and punching him in the back of the head.
He was also handcuffed and put in the back of a police vehicle.
District Judge Amanda Pilling said Marsh had used "gratuitous violence" and his actions were not "necessary, justified or proportionate".
She said Mr Attanayake "barely had time to begin to understand what was happening".
Marsh, of Canvey Island, Essex, was charged following an investigation by the Independent Office for Police Conduct (IOPC).
He has been on restricted duties.
The IOPC said Mr Attanayake "was a law-abiding member of the public, who had called the police to report a crime, when he became a victim of mistaken identity".
It said it was in "correspondence with" the Met Police "over whether PC Marsh should also face a misconduct hearing".
