It began on a bright spring day with the rumble of armored vehicles through the trailer park; when they rolled to a stop, they emptied a swarm of FBI SWAT agents in full tactical gear.

Eight months later, in the order and calm of a federal courtroom in Minneapolis, the story of that day in May started coming to a close. Buford “Bucky” Rogers, a lanky high-school dropout who the government once claimed had schemed to raid a National Guard armory and blow up a police station, politely pleaded guilty in a deal with prosecutors.

Rogers, 25, of Montevideo, Minn., admitted Friday that he possessed a gun he wasn’t supposed to have — thanks to a 2011 burglary conviction that made him a felon — and that he built and possessed two black powder-and-nails bombs.

In return for his guilty plea, federal prosecutors will drop two counts accusing him of possessing three other bombs that he had not bothered to register with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

The plea came three days before Rogers’ trial was to start. What began as a case in which the government warned of a well-armed militia plotting havoc boiled down, in the words of defense attorney Andrew Mohring, to “a case of simple possession.”

U.S. District Judge Ann Montgomery advised Rogers of the rights he was giving up by pleading guilty; he answered her questions clearly with a “No, ma’am” or a “Yes, ma’am.”

She asked him if he was guilty of each count. He said he was.

“You’re not taking the rap for anybody else?” she asked.

“I’m guilty, Your Honor.”

The judge denied Mohring’s request to release his client until sentencing. No date for that has been set, and Montgomery told Rogers that if he was serious about wanting to make a new start in life, he’s better off staying in jail until he’s sentenced.

The reason: She explained he will be getting prison time, and the time he spends in jail gets deducted from his sentence.

“It makes much more sense to me to get that time behind you,” she told him.

Rogers’ parents and fiancee (she and Rogers have a 13-month-old son) were in court for the 45-minute hearing. When the judge told the defendant she wasn’t letting him out, his father, Jeffrey Rogers, 58, let out a heavy sigh.

The family declined to comment after the hearing.

Under terms of the deal, prosecutors said they will argue that sentencing guidelines call for a prison term of 41 to 63 months. Mohring told the judge he was reserving the right to argue for less.

Mohring, an assistant federal public defender, pointed out that the government agreed that the so-called “terrorism enhancement” doesn’t apply to Rogers. The provision of the federal sentencing guidelines allows a judge to hand down far stiffer punishment than what the underlying crime normally would call for.

All the local defendants convicted of aiding the group al-Shabaab in Somalia were sentenced under the terrorism enhancement; some got up to 20 years in prison and will be on supervised release for the rest of their lives.

In Rogers’ case, a terrorism enhancement could’ve sent him to prison for nearly 22 years.

When the FBI raided the Montevideo mobile home where Rogers’ parents live on May 3, they said they were thwarting a domestic terrorism plot. In public pronouncements and court documents, the government said Rogers led a protest outfit called the Black Snake Militia and was bent on violence.

Rogers posted cryptic and misspelled warnings on Facebook (“Ever (sic) one better get your guns ready cuz there comeing (sic) FEMA,” he posted June 15, 2011) and his parents had a sign with the letters “BSM,” the militia’s initials, outside their mobile home.

The FBI claimed Rogers had schemed to raid the National Guard Armory in Montevideo, headquarters of the 1st Battalion, 151st Field Artillery of the Minnesota Army National Guard.

Agents also claimed he had discussed blowing up the city’s police station and toppling a communications tower.

The May 3 raid, which involved almost 50 officers from several law enforcement agencies, was needed because the attacks were imminent, the government claimed.

As it turned out, the Black Snake Militia had, at most, five members — one of whom apparently quit, went home to Texas and turned government informant.

In legal filings, Mohring blasted the informant as less than reliable. Mohring noted that the FBI never came up with enough probable cause to seek a search warrant for the Montevideo house where Rogers lived with his fiancee and child.

In the end, Rogers pleaded guilty to possessing a Romanian-made AK-47 knockoff. He’s not allowed to have firearms because of a 2011 guilty plea to burglary in Lac qui Parle County. He was on five years’ probation in that case when agents arrested him.

Rogers also admitted he built and possessed the two destructive devices made of black powder and packed with nails that were found at his parents’ trailer.

The plea deal came with a caveat: Rogers reserves his right to withdraw his guilty plea if an appeals court determines that statements he made to an FBI agent would have been inadmissible at trial.

Montgomery had thrown out some statements, saying the FBI should have read Rogers his rights before they questioned him. Agents can question a suspect without advising him of his rights if they believe there is an imminent threat to public safety.

The judge ruled, though, that with the raid on the mobile home and the discovery of the bombs, any imminent threat had passed. She said jurors would be allowed to hear the portion of the interrogation that took place after Rogers was read his rights, but Mohring is contesting the admission of those statements, too.

David Hanners can be reached at 612-338-6516.