In April, the township of Diepsloot, to the northwest of Johannesburg, made the headlines after a mob went from door to door, ostensibly on an anti-crime crusade in protest of escalating crime in their neighbourhood. At the conclusion of what turned out to be a deadly mission, Zimbabwean national Elvis Nyathi had been murdered in that most callously barbaric manner, burnt alive.

The manner of his death brought back bad memories of the necklacing, a horrible method of execution preferred by mobs seeking instant justice at the height of the anti-apartheid violence in the townships in the mid-1980s...