Two men have been arrested on suspicion of murdering a 15-year-old boy 12 years ago.
Billy Cox was shot dead in his bedroom in Fenwick Place, Clapham, on Valentine's Day in 2007.
He was found fatally injured by his younger sister, then aged 13. There was no sign of forced entry into the house.
On Tuesday two men aged 26 and 31 were arrested on suspicion of his murder and taken to a police station in south London to be questioned. The force said the men were detained "following developments within the investigation".
Officers from the Metropolitan Police did make arrests in June 2007 during the original investigation into Billy's death - four for suspected drug dealing and one on suspicion of murder - but no charges were brought.
Anyone with information can call police on 020 8785 8286, tweet @MetCC, or call Crimestoppers anonymously on 0800 555 111.