A 23-year-old man has been arrested on suspicion of the murder of Sergeant Matt Ratana, the Metropolitan Police said.
Sgt Ratana was killed when he was shot by a handcuffed suspect at Croydon Custody Centre in south London in the early hours of September 25.
That night, a 23-year-old man, who had been arrested for a separate offence, was detained by officers at Croydon Custody Centre and then taken by ambulance to hospital with a gunshot wound.
No police firearms were discharged during the incident.
The man’s condition, originally critical, has since stabilised and is no longer considered life-threatening. On Friday he was considered fit to be arrested on suspicion of murder.
As he man remains in hospital, officers will liaise with the relevant medical and legal teams to make an assessment of when he will be fit for interview.
Specialist family liaison officers from the Met’s Specialist Crime Command are in regular contact with and supporting Matt’s partner, his son and wider family. They have been informed of today’s arrest.