FBI agents recently warned community leaders in the Detroit area about a possible racist plot by a convicted felon and alleged neo-Nazi sympathizer who was arrested after he was discovered with an arsenal of assault rifles and other weapons, a law enforcement official tells NBC News.

“The FBI averted a catastrophe in this case, there’s no doubt about it,” Steven M. Dettelbach, the U.S. attorney in Cleveland, said in an interview.

New details about the case of Richard Schmidt, the owner of a sporting goods store in Bowling Green, Ohio, dramatically highlight what law enforcement officials say are major loopholes in the nation’s gun laws. Schmidt, 47, is a convicted felon who spent 13 years in Ohio state prison for a homicide after being convicted of killing a man and wounding two others in a shooting during a traffic stop, according to state prison records. Under federal law, Schmidt, who was released on parole in 2003, is barred from possessing any firearms.

Yet when FBI agents last December searched his home and store, they discovered a cache of 18 weapons that included AR-15 assault rifles, 9 mm Ruger and Sig Sauer pistols, shotguns, high-capacity magazines and more than 40,000 rounds of ammunition. Schmidt was originally reported to have been arrested on charges of trafficking in counterfeit goods, but was indicted last month on four federal charges —including possessing illegal weapons, body armor and ammunition. He has pleaded not guilty to the charges.

“As a matter of policy, I don’t comment on pending cases,” his lawyer, Andy Hart, a federal public defender in Toledo, said when reached by telephone.

Dettelbach, who is overseeing the case, said that federal agents have been unable to determine how and where Schmidt obtained his weapons, prompting officials to conclude he likely acquired them at gun shows or through private sales — where under federal law no background checks are required.

“It’s scary,” he said about Schmidt’s arsenal of weapons. “It’s not … that I won’t say” where Schmidt got his guns. “It’s that sitting here today as a senior federal law enforcement official in northern Ohio, I can’t say.”

The investigation into Schmidt was conducted by a FBI Joint terrorism Task Force whose agents said they discovered he was tracking African American and Jewish leaders in the Detroit area. When agents conducted their search, they said they found evidence suggesting Schmidt harbored neo-Nazi sympathies, including a video of the 2005 national meeting of the National Socialist Movement — in which speakers wore black swastika arm bands and gave the Nazi “Sieg Heil” salute. “This is a war! This is a battle for our survival!” one speaker shouts on a video of the meeting obtained by NBC News. Other seized items, according to federal search warrants, included a list of national Jewish-owned businesses and paraphernalia from the “Waffen SS,” Adolph Hitler’s military force in Germany.

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