Tyreece Wolfries-Parkin, 18 of Rothesay Road, SE25, was arrested on Monday, 22 March.
He was charged later the same day with the murder of Lavaun, who was found with fatal stab injuries in Wisbeach Road, SE25, at approximately 8.10pm on 5 February.
Wolfries-Parkin has also been charged with the attempted murder of a 16-year-old boy and possession of a bladed article.
He is due to appear at Bromley Magistrates’ Court on Tuesday, 23 March.
Tyreece Riggon, 20 of Armistice Gardens, SE25 and Julian Russell, 22 of Sanfield Road, CR7 have also been charged with the murder of Lavaun Witter as well as wounding with intent to cause grievous bodily harm of a 16-year-old boy and possession of a bladed article.
They appeared at Bromley Magistrates’ Curt in 20 February and were remanded to appear at the Old Bailey on 10 May.