The officer, who has not been identified, died after being rushed to hospital following the incident at the Croydon Custody Centre in Windmill Lane just after 2am on Friday. A 23-year-old man has been detained.
Commissioner Cressida Dick and Home Secretary Priti Patel shared tributes to the officer. Ms Patel said: "I am deeply shocked and saddened to learn that a Metropolitan Police Officer has been shot and killed in the line of duty.
“This is a sad day for our country and another terrible reminder of how our police officers put themselves in danger each and every day to keep the rest of us safe."
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