The Metropolitan Police has issued a new picture of PC Andrew Duncan, who died following a suspected hit-and-run collision in Sutton.
A further two men have been arrested in connection with the crash, after another was remanded in custody accused of causing death by dangerous driving.
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Six people were injured after they were hit with the substance during an "altercation" between two groups at a shopping in east London.
Save Your Uber in London was set up after it was announced the firm would not have its licence renewed when it expires next week.
Survivors are still traumatised, homeless and want answers.