An officer with the London Metropolitan Police Department was gunned down inside a department station house in the Croydon neighborhood on Friday morning, the agency said in a statement.
According to the Washington Post, a subject who had been arrested and was being processed suddenly produced a firearm and shot one of the attending officers.
The officer—whose name has not yet been released—was treated by other officers present and then transported to a nearby hospital where he subsequently succumbed to his wounds.
The gunman was also taken to a local hospital with what were termed as non-life-threatening injuries.
The police officer in Croydon is the 17th officer from the London Metropolitan Police to be killed by a firearm since the Second World War, according to records maintained by the BBC.