JOHANNESBURG - Tonderai Ndira was a shrewd choice for assassination: young, courageous and admired. Kill him and fear would pulse through a thousand spines. He was an up-and-comer in Zimbabwe’s opposition party, a charismatic figure with a strong following in the Harare slums where he lived.There were rumors his name was on a hit list. For weeks he prudently hid out, but his wife, Plaxedess, desperately pleaded with him to come home for a night. He slipped back to his family on May 12.

The five killers pushed through the door soon after dawn, as Mr. Ndira, 30, slept and his wife made porridge for their two children. He was wrenched from his bed, roughed up and stuffed into the back seat of a double-cab Toyota pickup. “They’re going to kill me,” he cried, Plaxedess said. As the children watched from the door, two men sat on his back, a gag was shoved in his mouth and his head was yanked upward, a technique of asphyxiation later presumed in a physician’s post mortem to be the cause of death.