SOUTHFIELD, Mich. (WXYZ) - The FBI and local law enforcement have taken a crack at a handful of tips over the last ten years.
In Michigan, four confirmed investigations have made the news.
- July 2003 – Hampton Township
There was a search in Hampton Township near bay city back in July of 2003.
Police were digging under a backyard swimming pool for a briefcase.A tipster had told them it contained a syringe and evidence that Hoffa had been murdered with drugs or poison.
Nothing was found.
- June 2004 – Detroit's Northwest Side
Investigators looked for clues at a home at Beaverland and Curtis on Detroit's northwest side.
They tore up the floorboards at the house.
They'd received a deathbed tip from an ex-Teamsters President from Delaware.
Again, they came up empty handed.
- May 2006 – Milford Township
The FBI investigated a tip that Hoffa's remains were buried on an 89-acre horse farm in Milford Township.
This was arguably the most extensive search to date.
It carried a price tag of more than $250,000.00, and the dig lasted for two weeks.
The FBI brought in heavy equipment, archaeologists, and anthropologists.
No remains were found.
- September 2012 – Roseville
Police turned their attention to a home in Roseville last year after receiving a credible tip.
Investigators used a ground-radar and detected what they called an 'anomaly' under the home's driveway.
They took soil samples and hand-delivered them to forensic experts at Michigan State University.
MSU's results showed no human remains were there.
Of course, rumors have swirled over the years about what may have happened to Hoffa.
Some speculated that his remains were buried under Giants Stadium in New Jersey, thrown in a swamp in Florida, and even sealed in the foundation of the Renaissance Center in Detroit.
With every search, though, the news is understandably painful for Hoffa's family.
He was declared legally dead in 1982 on the seventh anniversary of his disappearance.