Tshephisho Kekana, 27, Cidraas Motseothatha, 43, Madimetja Legodi, 37, and Victor Mohammed, 51, face one count of murder and three counts of attempted murder.
Mthokozisi Ntumba was gasping for air, had a wound on his face, blood on his shirt and a wound on the left side of his chest, when a doctor examined him shortly after police allegedly shot him.
The trial of four police officers accused of the murder of Mthokozisi Ntumba during student protests last year started in the Johannesburg high court on Monday.