It was 2:30 in the morning when Glenn R. Ellis heard the alarm. Someone was trying to break into his SUV. He picked up his 9mm handgun, ran outside his Laurel apartment and took aim.

When he stopped shooting that night last September, a 16-year-old was dead and a second young man wounded. Yesterday, Ellis, 38, was sentenced to 14 years in prison for the shootings. He offered an apology to the family of the teenager he killed but told the judge that he, too, was a victim.

"I did what I had to do because I was afraid for my life," Ellis told Prince George's County Circuit Judge Ronald D. Schiff. "They should have stayed home."

"I recognize you are somewhat of a victim in this case," Schiff said before announcing the sentence, which was agreed to as part of a plea bargain.

"However, you have placed yourself in the position of being the judge, jury and executioner in this case," the judge continued. "We live in a civilized society. We can't condone vigilante justice."

In April, Ellis pleaded guilty to voluntary manslaughter, attempted voluntary manslaughter and using a handgun in a crime of violence in the death of Ernest Sockwell, 16, and the wounding of Eron Harris, now 23.

Hours after the Sept. 3 shooting in the parking lot of his Laurel apartment building, Ellis said that his blue 1999 Chevrolet Tahoe had previously been vandalized and that he "had had enough." Sockwell and Harris both were shot in the back while trying to run away, prosecutors said. Two young men with them escaped unharmed.

After he pleaded guilty in April, Ellis told reporters that when he got close to his truck, "I saw a gun. I heard a shot. I returned fire." Police and prosecutors said there was no evidence that anyone other than Ellis fired or had a gun.

Ellis, a former tow truck driver for the D.C. Department of Public Works, said he pleaded guilty only because he could have been sentenced to 50 or 60 years in prison if he had been convicted of a third crime of violence. In the 1980s, Ellis was convicted of assault with intent to maim and assault with intent to disable, according to Prince George's court records.

The shooting received wide public attention in part because of a burgeoning problem in Prince George's County with car thefts. The county leads all jurisdictions in the Washington region in car thefts, with more than 33,000 vehicles stolen in the past two years, officials said.

After the shootings, some area residents expressed sympathy for Ellis on radio talk shows. Ellis, seeking a pardon, sent a petition with dozens of signatures to Gov. Robert L. Ehrlich Jr. (R), attorneys said.

Yesterday, State's Attorney Glenn F. Ivey said Ellis had to be held accountable.

Ivey said Ellis's SUV was equipped with an anti-theft device attached to the brake pedal. Someone would have needed a blowtorch to remove the device, Ivey said. The most that would-be thieves could have stolen would have been the SUV's stereo, Ivey said.

"You can't kill someone over property, and you certainly shouldn't shoot someone in the back over a car radio," Ivey said.

The gun charge Ellis pleaded guilty to carries a mandatory sentence of five years. Ellis's attorneys said he could be eligible for parole after about seven years.