The Metrobus driver had reached the end of the 9E route at the Pentagon on Wednesday when a group of people stepped to the door of the bus. They weren’t passengers. They were federal marshals.

The driver, Stacy L. Reed, 43, of Manassas, was asked to step off, and he was arrested in connection with the high-profile killing of a handyman who died defending a Centreville family from home invaders in 2010, authorities said.

Reed, who has been a Metrobus driver since August, played a key role in the botched conspiracy to burst into the home of the owner of nine Northern Virginia check-cashing stores to rob him of his business proceeds, according to court records.

But the family’s handyman and the son of the homeowner discovered two armed men — Tasheik Champean and Reynard Prather — in the garage on May 17, 2010.

The handyman, Jose Cardona, wrestled a gun away from one of the men, but the second conspirator turned his weapon on the family’s mother and demanded that Cardona return the pistol. Cardona complied — and was then fatally shot.

The Guatemalan immigrant was a father of two and hoped to eventually return to his home country, build a home and resume life as a farmer. He was described as a devout Christian.

“The arrest gives us a lot of relief and a lot of closure,” said Baljit Brar, a member of the family that was the target of the robbery. “We are hoping authorities can finally discover who sent these men to rob our home.”

Reed allegedly gathered information and planned the robbery with Champean and then drove Champean and Prather to a location near the Centreville mansion on the day of the robbery, according to court records.

A fourth unidentified conspirator drove Champean and Prather away after the failed scheme, according to court documents.

Federal authorities declined to discuss how the group learned that the Brar family kept money in their home, but Champean told Prather that his take would be at least $50,000, according to court records.

Reed made a brief appearance in federal court in Alexandria on Wednesday but had not been assigned an attorney.

He answered a judge’s questions but did not comment on the charge against him — conspiracy to commit a robbery, which carries a maximum penalty of 20 years in prison. He is scheduled for a preliminary hearing Monday.

His relatives did not return calls for comment.

Caroline Lukas, a Metro spokeswoman, said Reed will be put on paid leave “pending the outcome of the case.”

Court records show that Reed has not been convicted of any felonies, but he did file for bankruptcy last year.

His arrest comes less than a week after Champean, 46, of Suitland pleaded guilty in U.S. District Court in Alexandria to charges of conspiracy to commit murder and armed robbery. He faces a maximum penalty of life in prison when he is sentenced in March.

Prather, 22, of Oxon Hill was arrested last year and was sentenced to 30 years in prison on the same charges.

On Wednesday morning, Reed was driving the 9E route, which runs between Huntington and the Pentagon, Lukas said. After he had pulled the bus into the Pentagon’s transit center and let the passengers off, he was approached by the U.S. marshals, who asked him to get off, Lukas said.

Reed was taken into custody without incident.

A Metro official said transit police and the federal marshals decided that the best place to arrest him was at the end of the line, instead of along the route, which would have disrupted passengers’ trips.

In hiring Metrobus operators, the transit agency runs criminal background checks and requires applicants to have a good driving record, complete a medical check and have good customer-service skills.