It happened in Camden, New Jersey in 1920.  Sixty-year old David Paul was carrying a satchel full of money for his employer.  He was to deliver it across the bridge to another company in Philadelphia, but he disappeared.  Over a week later, some hunters found his body near a stream, buried in a shallow grave.  He'd been beaten and shot.  Although the ground was dry, his clothing was soaked, and there were tire tread marks nearby.

What surprised investigators was that the time of death was estimated at approximately twenty-four hours before he was found.  That meant that he'd been missing for nine days before he was killed.  It appeared that he'd decided either to leave with the money and had been killed in the process, or he'd been held some place against his will before being murdered.

The detective on the case, Ellis Parker, thought the time of death estimation was flawed.  He used clues from the scene to come up with a better theory, and managed to trace a pair of glasses to Paul's neighbor, Frank James.  James appeared to be in cahoots with another man, Raymond Schuck, and they had been seen together spending large sums of money.   However, both had alibis for the estimated time of Paul's murder.

Parker then looked at tanning factories on the stream, and the water yielded a high content of tannic acid, a strong preservative.  If the body had been submerged in it, decomposition would have been retarded, foiling the medical examiner's typical methods for determining time of death. 

When confronted with the likelihood, James confessed.  He said that he and Schuck had dumped the body in the water, but later had retrieved and buried it.  Both were convicted and sentenced to death.