Two men have been arrested on suspicion of the murder of Trevor Ellis, the 26-year-old father-of-four who became the riots' first fatality.
Mr Ellis suffered a gunshot wound to the head in Croydon, south London, on Monday night. He died the next day.
Scotland Yard said that a 26-year-old was arrested in Mitcham, south London yesterday, by police supported by armed officers from CO19. He remained in custody at a south London police station last night. A 24-year-old, arrested in Brighton, has been bailed to return on 12 September, pending further inquiries.
A Scotland Yard spokesman said initial inquiries suggested Mr Ellis, of Brixton Hill, south London, had travelled to Croydon with friends. He said: "It is believed the group became involved in an altercation with a group of approximately nine individuals.
"This altercation culminated in a vehicle pursuit involving three vehicles, passing into Duppas Hill Road, where the victim was shot."
Detectives are appealing for anyone who witnessed the pursuit involving a dark estate car, a silver hatchback and a dark hatchback, in which Mr Ellis was a passenger.