Glinda McKoy approached the witness stand yesterday in Prince William County Circuit Court and walked with a slight quiver as she passed in front of one of the men who killed her son Maurice. Inside, she carried indignation and, in a twist of fate, Maurice's kidney, which helped prolong her life.

Romayn K. Robinson, who authorities said was one of two men who meant to shoot another person as payback for a fistfight, sat with his head low at the defense table.

"He's going to jail for what? Over some stupid fight?" Glinda McKoy, 52, asked the prosecutor and judge. "At least he gets a chance to start over again. My son don't."

Robinson, 22, of Dale City, pleaded guilty to voluntary manslaughter and weapons charges yesterday and was sentenced to 15 years in prison in Maurice McKoy's slaying last year. McKoy, a former high school football running back, was shot once in the head while he was playing video games in his Woodbridge townhouse on Jan. 9, 2003. Doctors kept him on life support for 24 hours before he died at Inova Fairfax Hospital.

Assistant Commonwealth's Attorney William Jarvis said the other gunman was Antonio J. Shaw, 23, of Dale City, who was sentenced this month to 27 years after being convicted on murder and weapons charges.

Asked whether he wanted to make any statements to the family, Robinson said in a low voice, "I can't say nothing."

Judge Rossie Alston looked sternly at Robinson.

"You bear some responsibility for the hurt [the McKoy family] always will have to suffer through," he said. "You did something horrible. He missed out on what some people consider the best years of his life."

Jarvis said Robinson's charges were reduced from first-degree murder to voluntary manslaughter because there is little evidence to prove who shot McKoy. Had the case gone to trial, Jarvis said, he would have shown that Robinson and Shaw were the only ones who brought guns to the townhouse in the 14000 block of Belvedere Drive.

A man who drove them to the townhouse would have testified that he saw "a number of flashes" coming from two guns, Jarvis told the judge. Charges against O'Bryan Woods, the driver of the car, are pending, Jarvis said.

McKoy, 22, who worked for a moving company, was the unintended target that January evening. The assailants meant to attack his friend Kenneth Snodgrass, who earlier that day punched Shaw in the mouth, police said.

"As a result, they got together and formed a plan to retaliate against Snodgrass," Jarvis told the judge. "They received information that he would be at [the townhouse] on Belvedere Drive."

Jarvis said Robinson was asked whether he wanted to join in the attack. Armed with a revolver, Robinson was picked up at his girlfriend's house. Woods then drove Robinson and Shaw to McKoy's townhouse, not knowing "what the purpose was."

They parked on a hill far from McKoy's townhouse in the early evening. Shaw got out of the car, retrieved a gun from underneath the hood and left for the townhouse with Robinson, Jarvis said. After Woods saw the flashes, Robinson returned to the car and told him that he "saw a head drop," Jarvis said.

McKoy "was sitting in front of the TV, minding his own business. He was not a target," Jarvis told Judge Alston. Snodgrass was sitting near McKoy and was not hit by gunfire.

Law enforcement authorities had few leads until a cousin of Shaw's serving time in prison told prosecutors that he had received a phone call from Shaw in which he confessed, Jarvis said.

At a court hearing last year, Woods, the driver, testified that he dropped Robinson off at his home after the incident and then drove Shaw to a sewer drain in the Lorton area, where Shaw allegedly discarded the weapon.

Typically, a sentencing hearing is scheduled weeks after a person has been convicted. But in an unusual step yesterday, Robinson's attorney, John D. Primeau, asked that his client's guilty plea be followed immediately with his sentencing.

Primeau said he made the request because he believed the judge was not going to shorten Robinson's prison time to less than the maximum sentence of 15 years. Prosecutors had already made concessions by reducing the murder charge and dropping two other weapons charges, he said.

Lee McKoy, the victim's brother, also took the witness stand yesterday and said that Robinson's act was "cowardly" and "selfish."

"I am not going to lie to you. I don't know him. I don't like him. I can't stand him right now," said Lee McKoy, 32, a truck driver.

After the hearing, Glinda and Lee McKoy said they wished Robinson received a longer sentence, possibly life in prison.

Glinda McKoy could not help but note something else as she left court yesterday: Maurice "gave me another life -- that's the irony of the situation."

Glinda McKoy, who received a kidney from her slain son, holds Maurice's son, Devon Johnson, 2, at her home in January 2003.