The Bureau of Alcohol, Tobacco, Firearms and Explosives is seeking the forfeiture of a machine gun taken from the owner of a Medford arms business, claiming it was purchased with expired credentials.

In April, an ATF agent seized a Glock Model 18 select-fire machine pistol built after 1986 from Guns R Us dealer Jonathan Purtzer, according to documents filed Monday in U.S. District Court in Portland.

Court documents allege that Purtzer purchased the weapon using an outdated letter from a previous Josephine County sheriff, moving forward with the purchase after the current Josephine County sheriff declined to send him a new letter.

The National Firearms Act requires buyers of machine guns made after 1986 to submit a letter from law enforcement dated within a year of the purchase, along with an application that includes the gun model and its intended use. In Purtzer's application, he said the gun was for demonstration purposes at the store, 259 E. Barnett Road, and he used a letter from former Sheriff Gil Gilbertson dated February 2014. 

Purtzer allegedly contacted current Josephine County Sheriff Dave Daniel on Nov. 28, 2015, for a new letter on department letterhead, telling Daniel he had found an automatic weapon and already bought it, according to a court document filed in September. Daniel reportedly refused.

"Sheriff Daniel denied Purtzer's request for the Law Letter and described the situation as 'shady,' " according to a statement filed in September by ATF agent Carmen Zobel.

Complicating the dispute is that the sale application was approved "erroneously" by a branch of the ATF last December, according to Zobel, and High Country Gunsmithing in Michigan shipped the weapon to Purtzer in January. According to court documents, Purtzer paid $3,475 for the gun through gunbroker.com.

In a court document filed Sept. 29, Purtzer denied any wrongdoing and demanded his firearm back. 

In a statement filed in court, Purtzer described himself as "the president of the corporation that owns Guns R Us" in Medford.

— Reach reporter Nick Morgan at 541-776-4471 or nmorgan@mailtribune.com. Follow him on Twitter at @MTCrimeBeat.