BART officer Anthony Pirone , kneed Grant in the head and forced the unarmed Grant to lie face down on the platform .

While Pirone held Grant down in a prone position , Mehserle drew Motion his pistol and shot Use_firearm Grant in the back .

Officer Pirone walked Self_motion up to two African American men and ripped Destroying the jacket off one .

Pirone threw Motion him and his friend against the wall and then turned to the train , yelling Motion for everyone involved Cause_to_be_included in the fight Hostile_encounter to exit the train and come to him .

Everyone remained Presence on the train , so Officer Pirone walked Self_motion into the train to see if there was anyone on the train who looked Change_sentiment as if they were involved Cause_to_be_included in the fight .

Pirone saw Grant dressed Wearing in a similar outfit as everyone else that was sitting Motion against the wall on the train platform and therefore removed Removing him .