Mr. Magaqa died about eight weeks later — from his injuries, the authorities said. His family insisted he had been recovering and was poisoned.
Of the nearly 40 politicians assassinated in South Africa last year, he was the most recognizable. The public broadcaster aired his funeral, five and a half hours long, live from a sports field. Hundreds came, including top A.N.C. politicians and a minister who flew in by helicopter.
The speeches were anodyne, or became rallying cries for the party. But Mr. Zulu had none of it. At a service beforehand, he said Mr. Magaqa had been killed for revealing corruption inside the party.
Today, fearing for his own life, Mr. Zulu sleeps in a different place every night. Two bodyguards, hired by his extended family, shadow him at all times. The three big men squeeze into his compact Volkswagen, which sinks a few inches every time they get in, as Mr. Zulu wages his one-man crusade against corruption.
“The A.N.C. is like an ocean that will cleanse itself,” he said, repeating it so often that he seemed to be trying to convince himself.
He, too, says he is fighting for what President Ramaphosa calls a “new dawn” for the nation. So why, he asked, has Mr. Ramaphosa remained silent on the Public Protector’s recommendations to provide him with security?
“I’ve been living like a hunted animal,” Mr. Zulu said.
In an empty, roofless room, wrapped in heavy blankets against the cold, Mr. Magaqa’s mother spoke about the promises A.N.C. officials made after her son died. His Mercedes sat in a corner of the backyard, riddled with bullets.