The trial of the man charged with carrying a loaded shotgun near the Capitol is expected to begin Monday after a longer-than-expected jury selection process.

Many potential jurors were disqualified for bias after they revealed they were familiar with Michael Gorbey’s arrest from seeing and reading media reports, according to a court official. Jury selection began on Wednesday morning and had been expected to be completed in time for the trial to begin this week.

Gorbey was arrested on Jan. 18 while walking toward the Supreme Court with a loaded shotgun, a sword and more than two dozen rounds of ammunition. He said he was on his way to a meeting with Chief Justice John Roberts.

Police have charged him with 15 counts, including manufacturing explosives and possessing a weapon of mass destruction. The latter two charges each could yield a maximum prison term of 30 years.

The explosives charges were brought against him after Capitol Police and FBI investigators said they discovered several shotgun shells taped to a canister of gunpowder behind the passenger seat of the truck they said Gorbey drove to Capitol Hill. The truck was parked a few blocks from the Russell Senate Office Building.

Gorbey filed a motion Tuesday that sought to prevent testimony by a government expert witness, FBI bomb unit examiner Daniel Hickey. Gorbey contends a report written by Hickey, which supports government claims that a potentially dangerous explosive device was found in the truck, mixes “innocuous facts with assumptions and speculation.”

Hickey’s report was issued after the Capitol Police bomb squad had neutralized an alleged explosive device in the truck. The device was disrupted for safety reasons, and Hickey wrote “the design of the device cannot be determined with certainty.”

At the same time, his report concluded the device was potentially dangerous. “However, based on the submitted evidence and the photographs available a logical functioning sequence can be surmised,” it said.