For a while, it looked like a gold rush—a small army of diggers descending on a 29-acre site some six miles west of Pontiac, Mich. They were led by state policemen ripping up great trenches with a rented backhoe, but among the scramblers were laid-off auto workers, housewives and after-school kids hacking away at the ground with garden tools. One man was seen digging with his bare hands. They were looking for hidden treasure of a sort—the body of former Teamsters' President James Hoffa, who has been missing since July 30.
For finding Hoffa, dead or alive, any private citizen could...