Michael Gorbey was convicted Friday on all 14 counts stemming from his January arrest for carrying a cache of weapons near the Capitol.

Now Gorbey faces decades in prison. Much of that time is for two charges: one for attempting to manufacture a weapon of mass destruction and another for possessing it. They relate to a homemade device found weeks after his arrest in a truck he drove to Capitol Hill.

Gorbey is the first person to be convicted of those charges since the D.C. law passed in 2002. He could get up to 30 years for each charge.

Sentencing is scheduled for July 25.

Though the verdict comes as no surprise to most observers, the trial garnered attention because of Gorbey’s constant outbursts and his unusual decision to represent himself.

Throughout the three-week trial, Gorbey argued that Capitol Police were involved in a government conspiracy against him. He said officers planted the weapons found on him when he was arrested Jan. 18: a loaded shotgun, a three-foot sword and 31 rounds of ammunition.

On Thursday, in his closing statement, Gorbey asked jurors to acquit him. The future of “our children” and constitutional freedom was at stake, he said.

“It should be easy to see that they are trying to be rid of me,” he said. “Now they are using you people to convict me.”

Gorbey is used to the courtroom; he had been convicted of seven felonies before this trial. Those convictions include arson, petty larceny and possessing a weapon as a felon.

When he was arrested, officers found him walking near First and D streets Northeast in a military flak vest, shotgun in hand. Capitol Police officers said he told them he was headed to an appointment with Chief Justice John Roberts.

The device found in his truck was located behind the seat in a follow-up search three weeks later at the Government Printing Office, where the truck had been parked. It was a tin can filled with black powder — shotgun shells, a glass bottle and pellets were duct-taped to the outside of the can.

Some officers testified that it wouldn’t have exploded because there was no fuse system. Firecrackers also found in the truck, however, fit into a hole at the bottom of the can, where they could have then been ignited, according to an explosives expert who testified at the trial.