One after another, the orchards near Yuba City, Calif., yielded their grisly secrets. Using shovels, a tractor and eventually even a light plane with an infra-red camera, police unearthed 25 decomposing bodies, mostly itinerant farm laborers, all hacked to death with a machete-like weapon. It was the worst series of murders in U.S. history.
Even before the last bodies were found, police arrested Juan Corona, 37, a Mexican farm-labor contractor who was a churchgoer, homeowner, and father of four girls. "We are sure that he committed the murders," said Sheriff Roy Whiteaker. That was...