By KRISTIN M. HALL

NASHVILLE — Investigators are trying to determine whether 100 pounds of military-grade explosives found at the home of an Army Special Forces soldier were taken from Fort Campbell.

Sgt. 1st Class Timothy Ryan Richards, 25, is scheduled to appear in federal court in Nashville on Thursday for a detention hearing for possessing two unregistered automatic weapons. Officials have said he may face more charges related to the explosives.

He was arrested Monday after a pair of hunters found the explosives, including a plastic explosive called C-4, near his home close to the installation on the Tennessee-Kentucky state line.

Alcohol, Tobacco, Firearms and Explosives Special Agent in Charge James Cavanaugh said they are working with Army officials to determine the source of the explosives.

“Just because a soldier lives near Fort Campbell, doesn’t mean it came from that facility,” Cavanaugh said.

But Richards also specialized in using explosives as part of his job as a senior engineering sergeant and would have trained others on how to use explosives, according to the Army.

Richards has been stationed at Fort Campbell with the 5th Special Forces Group for six years and has deployed three times to Iraq, according to Maj. April Olsen, a Special Forces spokeswoman.

Special Forces units are called Operational Detachment Alphas and each soldier in the unit has a specialty, such as medical or weapons skills.

His specialty as an engineer means he would have been trained to use explosives for a variety of reasons, such as demolition, and he would cross train others in the unit on those skills, Olsen said. Other duties he would have had would be construction, electrical rigging and map surveying.

Cavanaugh said the Army is diligent about investigating when weapons or ordnance is missing or is stolen.

Another Fort Campbell soldier was arrested in October and charged with selling four hand grenades and an anti-tank rocket that were stolen from the installation. Undercover federal agents arranged the sale with Pfc. Joshua Bartlett Etherton after police in the small town of Paris received a tip.

“The commanding general locked that place down after that to do inventory of the ordnance,” Cavanaugh said.

Kelly Tyler, a Fort Campbell spokeswoman, declined to comment on either case because they were ongoing investigations and said it would be premature to assume that the explosives came from Fort Campbell.

All ammunition and munitions are stored at an Ammunition Storage Point on post and access is limited and highly controlled, Tyler said.

All units must sign for the release of ammunition or munitions for use in training on one of the post’s artillery ranges. The unit either turns in whatever it doesn’t use or provides proof that all the ammo or explosives were properly expended.

Tyler said once the munition leaves the storage area, it becomes the responsibility of the commander of the unit to properly account for it.

Cavanaugh said that considering the thousands of people who rotate in and out of Fort Campbell, home of the storied 101st Airborne Division, very little ordnance goes missing.

The material was sealed in watertight containers and partially buried near Richard’s home outside of Clarksville.

Agents also found a 5.56mm caliber rifle and a .45 caliber machine gun, both fully automatic, inside his home.

Cavanaugh said they were still trying to determine what he intended to do with the explosives, but Joel Siskovic, a spokesman for the FBI in Tennessee, said agents determined there was no terrorism connection.