FBI agents seized bomb-making materials, seven guns and ammunition from the Montana home of a man they suspect of carrying out bank robberies in five states, according to an inventory list filed with a federal court.

The property seized from Richard Gathercole's home in Roundup shows that agents also found sheriff's badges and patches, a sheriff's vest, an ammunition vest, a military style helmet, an organic chemistry book and material to make identification badges.

Authorities believe Gathercole, 39, is the man they call "the AK-47 bandit" who held up at least six banks since 2012 in California, Washington, Idaho, Nebraska and Iowa. The suspect typically wore a mask with only his nose and eyes showing and carried an AK-47 rifle with a drum magazine.

Gathercole is being held in Lexington, Nebraska, where he is accused of stealing a truck and guns and firing on a Kansas state trooper who was trying to pull him over for a traffic stop last month.

The inventory list filed with U.S. District Court in Billings on June 27 listed 39 seized items, including computers, books and other documents. It does not include details of the improvised-explosive device material that was found other than "IED components."

Travis Burrows, the FBI's senior supervisory resident agent in Billings, said a total of seven explosives were found in Gathercole's home, and a bomb squad detonated them all.

The search warrant filed with the court said one explosive device was used in a 2015 bank robbery in Iowa and contained powder, metal pieces and a fuse.

Gathercole is scheduled to appear in court in Nebraska on Thursday on both a fugitive from justice charge related to the attempted shooting of the Kansas trooper and on the theft charges.

His public defender, Corey Burns, said Wednesday that the preliminary hearing will only determine whether there is probable cause to file those charges, and that Gathercole will not enter a plea.

He declined to discuss Gathercole any further without his client's permission, other than to say, "He is doing well."

Federal charges related to the bank robberies have not been filed. Last week, San Bernardino County, California, prosecutors said they planned to charge Gathercole with attempted murder of a peace officer for the shooting of a Chino police officer during a 2012 bank robbery.