CLARKSVILLE, Tenn. -- Investigators said the 100 pounds of explosives found on a Fort Campbell soldier's property were sitting on the lot for months without the military knowing they were missing.

Investigators: Military Didn't Realize Explosives Missing | Video: Soldier Arrested After Explosives Found Near Home

Alcohol, Tobacco, Firearms and Explosives investigators found the Composition 4, an efficient and powerful explosive designed for destruction, on a 19-acre lot belonging to Special Forces soldier Timothy Richards.

"He admitted to us that the explosives, he placed there, that he had put them there in those containers," said Jim Cavanaugh, special agent in charge, ATF Nashville Division.

Cavanaugh said the military-owned explosives had been sitting there for months.

"There's probably such large volumes of explosives, you know, unless you get a report of a break-in at a military magazine or something, we wouldn't know," Cavanaugh said.

He said people should rest easy knowing investigators have no reason to believe Richards has any other explosives hidden on his property. They also don't believe he was involved in a terrorist-type plot.

"We don't see any cause for additional alarm based on this case," said Cavanaugh.

Investigators won't say if Richards was planning to sell the explosives on the black market, but they did say the idea isn't far fetched.

Last month, undercover officers purchased a stolen rocket and four grenades from another Fort Campbell soldier near Paris, Tenn.

Along with the 100 pounds of C-4, investigators also caught Richards with a Swedish machine gun and an unregistered rifle.

Richards is facing illegal possession charges, but investigators said to expect to see more charges tacked on to the list.