One bullet in Lathaniel’s chest caused “catastrophic” internal bleeding, and he collapsed and died after attempting to run away.
Prosecution barrister Alan Gardner KC had told jurors: “The gunman would have fired more shots but his firearm malfunctioned and disintegrated, leaving parts behind at the scene which were later found by the police.
“However, the two shots he did fire were enough to achieve what the gunman intended – Lathaniel died at the scene, despite the best efforts of members of the public and emergency medical staff.”
Gardner told the court the murder was a “planned, organised and premeditated shooting” by Duodu-Watson and assisted by Prempeh.
He was the driver of a white Nissan Juke car which was used to drive the gunman to and from the scene.
Jurors were told Prempeh’s car had a specially constructed hiding place which was an ideal place to conceal a gun.
The defendants used a “trap house” (a premises where illegal drugs are sold) as a base before and after the shooting, the court heard.
The Just Eat jacket worn by the gunman was linked to that address and following a search, police found live ammunition in one of the bedrooms.
On a possible motive for the killing, Gardner suggested its origins lay in the trade in illegal drugs and had “many of the hallmarks of serious organised crime”.
Following an Old Bailey trial, Duodu-Watson, from Peckham, and Prempeh, 33, from Forest Hill, were found guilty of murder on Friday.
Both men were remanded into custody to be sentenced at a later date