A self-styled militia leader in Nevada who set off homemade bombs in the Arizona desert and bragged about wanting “to go to a nursery school and use kids for target practice” has pleaded guilty to a federal firearms violation.

Steven Matthew Fernandes, 19, who said he was a member of the Southern Nevada Militia when he was arrested by the FBI in September 2012, pleaded guilty this week in U.S. District Court in Las Vegas to possession of an unregistered firearm.

Two other federal charges he was facing – illegally making firearms and transportation of explosive material – are expected to be dismissed as part of a plea agreement with federal prosecutors. They are expected to recommend an 18-month sentence when Fernandes is sentenced in December. The charge carries a maximum of 10 years and a $10,000 fine.

The plea agreement says on Sept. 13, 2012, and prior to that, Fernandes possessed and made destructive devices containing explosive materials at his house in Las Vegas. The defendant also possessed parts and materials that “could be readily assembled” into illegal explosive devices in violation of federal law, the public document says.

At the time of his arrest, FBI agents said they recovered five rifles, four handguns and “thousands of rounds of ammunition,” along with an array of bomb-building materials and instructions” from the suspect’s bedroom in a house where he lived with his divorced mother. She had installed a dead bolt on the room, apparently to keep the suspect’s two younger sisters away from the arsenal he had amassed.

His familiarity with firearms, court document says, stemmed from his involvement with a Boy Scout law enforcement “Explorer Post.” Fernandes, who claimed he had made at least 69 pipe bombs and talked about building poisonous chlorine gas bombs, used a “special purchasing code” from his high school to buy restricted chemicals from suppliers, the document says.

In entering his guilty plea this week, Fernandes confessed to transporting his homemade bombs in Nevada, Utah and Arizona, where he detonated the devices.

Prosecutors said a confidential source provided the FBI with an e-mail from Fernandes in which he “described himself as the commanding officer of the 327th Nevada Militia, an urban survivalist unit with six or seven members,” the Las Vegas Review-Journal reported.

His defense attorney, Crystal Eller, said a psychiatric evaluation proved Fernandes was not a threat to himself or the community. She contended her client, who was scheduled to join the U.S. Marines two days before his arrested, “was regarded as a “very responsible and grounded teenager,” the newspaper reported.

“This is someone who sees himself as a fighter for this country, not a terrorist,” Eller told the Las Vegas newspaper.

His plea came after the June guilty plea of Fernandes’ friend, Jake Howell, to a gross misdemeanor charge of possession of a dangerous weapon on school property.

After a shooting spree at a movie theater in Aurora, Colo., in July 2012, that left 12 people dead and 58 others injured, Fernandes boasted, “I’ll beat that record,’’ other court documents say. Fernandes also boasted that his high school classmates in Las Vegas considered him “most likely to show up to school and just start killing people.”