Blayne Shepard, 23, his brother Kyle, 25, Andries van der Merwe, 23, and Dustin van Wyk, 23, are accused of beating Williams to death outside Kings Park stadium on the night of March 23 last year, after a rugby match.
The four each face a charge of murder, three of assault with intent to do grievous bodily harm, and one of crimen injuria.
Last week, Baoto Ifomba, a security guard on duty testified about the deadly assault.
He said a verbal altercation appeared to take place between Williams and a crowd of people, before he was attacked: “They were assaulting him, kicking him. Someone came with a brick and the deceased was lying on his back. When I stood up they were still kicking him.”
Paramedics were unable to revive Williams after the assault.
Previously, Warrant Officer Craig Bekker testified Williams was involved in at least four scuffles the night he was killed.
One of the men whom Williams had allegedly fought with on the night, Grant Cramer, was initially charged with assault but has since turned State witness.