The 17-year-old’s life support was turned off last Thursday at Royal Perth Hospital because of injuries after an item was allegedly thrown at him from close range.
The alleged offender appeared briefly in Perth Magistrates Court on Saturday and is due to re-appear on March 2.
Police found Kuol unconscious on Hainsworth Avenue about 11.45pm.
Detective Senior Sergeant Tom Mills said the alleged assault occurred at the intersection of Meakers Way and Hainsworth Avenue.
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READ NOWThe victim, who had a South Sudanese background, had attended an 18th birthday party in the area.
The party finished about 11pm, with about 180 guests leaving the Hainsworth Avenue house.
Sen-Sgt Mills thanked a co-operative local South Sudanese community.