Darnella,now 18 was among one of four young witnesses to take the stand on the second day of Derek Chauvin’s trial.
She told the court of seeing Mr.Floyd beg for his life and comparing that moment to her dad,brother,cousins and uncles because they are all black.
Defence lawyers have indicated that they will argue that the 46 year old died of an overdose.
Mr.Chauvin has denied charges of murder and manslaughter.
The three officers who were present Tou Thao, J Aexander Keung and Thomas Lane will go trial later in the year.
On the second day of the trail four children all under 18 years at the time of the incident gave evidence to the court but cameras were off and were referred only by names.
Darnella then 17 years was walking to Cup Foods with her nine-year-old cousin when they came across the arrest scene on the street outside.
She told the court she saw a man beg for his life and that he could not breathe.
Darnella said witnessing his death changed her life.