A court’s heard Elianne Andam’s suspected attacker pulled out a knife like a character from TV series Top Boy.
She begged him to ‘stop’ before she was killed.
The 15-year-old schoolgirl was stabbed to death in Croydon last September, in what prosecutors say was a row over a teddy bear.
Pc Peter Nolan arrested Hassan Sentamu, who is now aged 18, and says he had blood on his thumb.