In what federal authorities are calling an unprecedented discovery, the FBI uncovered the largest cache of homemade explosive devices in its history during a raid on a Virginia property earlier this month.

The FBI is working to determine the plans of a 36-year-old suspect after investigators discovered over 150 explosives, primarily pipe bombs, on his 20-acre farm. According to the FBI, this is the largest cache of explosives ever found in the bureau’s more than 100-year history.

Investigators discovered more than 150 devices, mostly pipe bombs, on a property outside Norfolk, court papers say.

Prosecutors say federal agents found one of the largest stockpiles of homemade explosives they’ve ever seized when they arrested a Virginia man on a firearms charge last month

The FBI has arrested a Virginia man after finding the largest stockpile of "finished explosive devices" in the bureau's history, according to court documents. Brad Spafford was arrested Dec. 17 at his farm in Smithfield.

Prosecutors are fighting to keep a Virginia man behind bars after they say investigators found what could be the largest number of “finished explosive devices” in FBI history at his 20-acre home near Norfolk.