The man investigators believe was the ringleader of a brutal attack that left a Virginia man dead and his wife clinging to life is facing capital-murder charges, the Loudoun County prosecutor announced Tuesday.

Anthony Roberts, 26, of Middleburg, Va., was also indicted on charges of rape, robbery, aggravated malicious wounding and other offenses in connection with the March 2009 killing of William Bennett, 57, and the assault on his wife, Cynthia Bennett.

The couple had gone for an early Sunday morning walk together along Riverside Parkway when three young men spotted them from a van and decided to rob them, one of the men later testified.

William Bennett, a former Army Special Forces soldier and retired lieutenant colonel, was found lying near the roadway, beaten to death. Sheriff’s deputies did not spot Cynthia Bennett, then 55, in the pre-dawn darkness for about 45 minutes, beaten but still alive in a grassy area about 50 yards from her husband.

The crime horrified residents of the serene Lansdowne community, east of Leesburg near the Potomac River. Within about a month, Loudoun sheriff’s investigators had targeted three teenage gang members: Jaime Ayala, then 17; Darwin G. Bowman, then 18; and Roberts, then 19. Ayala, picked up after an unrelated gang fight, told detectives, “I didn’t beat them; I was just driving.”

Anthony Roberts (Loudoun County Sheriff's Office)

Ayala claimed, according to sheriff’s investigators’ testimony in 2009, that he had picked up Bowman and Roberts in Leesburg, and they reported they had just robbed a woman. “There was discussion about ripping someone else, looking to rob someone else,” Investigator John H. Smith said Ayala told him. Then, they spotted the Bennetts walking alone.

Ayala, an admitted member of the 18th Street gang, said that Bowman and Roberts got out of the van and disappeared for 20 minutes. When Ayala pulled the van ahead looking for them, he saw Roberts beating William Bennett while he was on the ground.

As Ayala drove away, Bowman and Roberts were laughing about their actions, Smith testified that Ayala told him. They later drove to an industrial park where Bowman and Roberts burned their bloody clothes with gasoline, Ayala told the investigator.

Ayala pleaded guilty in 2011. At his sentencing, Cynthia Bennett said that because of severe nerve damage to her leg and drastic internal injuries, “I’m not able to do things I used to be able to do.” The trauma surgeon who treated her testified that he had never before seen such horrific injuries, describing her survival as a medical miracle. She needed plastic surgery on her face and was unable to return to work. “It’s just living in a different world than I used to live in,” Cynthia Bennett said.

The judge gave Ayala a life sentence plus 40 years for second-degree murder. In 2013, facing capital-murder charges, Bowman pleaded guilty to first-degree murder. He was sentenced to 43 years in prison. “I take full responsibility for everything, and I’m so sorry for everything,” said Bowman, also an 18th Street gang member.

Ayala and Bowman agreed to cooperate with prosecutors as part of their pleas. Roberts has been in prison since December 2009 for a Leesburg gun-store burglary.

On Monday, the Loudoun grand jury indicted Roberts on five capital-murder counts, incorporating five theories of the crime that could lead to the death penalty, Commonwealth’s Attorney James E. Plowman (R) said.

Plowman added that indicting Roberts took an extended period because, after obtaining the pleas of Ayala and Bowman, he was preparing to try the case. Once an indictment is filed, Virginia’s speedy-trial law begins and prosecutors have five months to try the case, though defense lawyers often ask for the clock to be stopped so they can prepare.

Plowman said he had readied pretrial discovery for Roberts’s defense consisting of 7,000 pages of information. The prosecutor did not know whether Virginia’s capital public-defender unit or private attorneys would be appointed to represent Roberts.