A 17-year-old Fairfax County youth was sentenced to 22 years in prison yesterday for shooting to death his 14-year-old girlfriend in what the prosecutor called a " 'Fatal Attraction'-type scenario."

David Marcus Fossett, who was 16 when he shot Summer Lawhead in the face with his father's gun last May, pleaded guilty in October to second-degree murder and using a firearm, just before he was to stand trial as an adult.

Yesterday, the diminutive youth with blond hair and pimples stood before Fairfax County Circuit Judge F. Bruce Bach and read a prepared statement, saying in part that he still loves Summer and that he did not mean to kill her.

But Bach, calling the crime "a horrible thing," said he did not believe for a minute that the May 7 shooting was accidental. The judge could have sentenced Fossett as a juvenile but chose instead the maximum penalty.

"I felt like it was very just and fair. I'm very pleased," Summer's mother, Helen Holt, said after the sentencing hearing. "I felt that the state saw what the truth was."

The prosecution maintained that Fossett, a 10th-grader at West Potomac High School known as Marcus, was obsessed with Summer and shot her because she was trying to end their six-month relationship.

"It was a 'Fatal Attraction'-type scenario," said Assistant Commonwealth's Attorney James P. Fisher. "She was just a kid. It was just sad and tragic she found herself in that situation."

Almost since the pair met in November 1990, Holt said, she had been trying to get her daughter away from the youth. Under his influence, she said, her daughter began doing uncharacteristic things such as skipping school.

In an interview in the courthouse cafeteria, Holt tearfully talked about her desperate effort to get her daughter away from Fossett. Because her ex-husband worked for the State Department, her daughter had lived 13 of her 14 years overseas, including in Bangladesh and Egypt, and met Fossett only a couple of months after moving to this country.

"Summer had seen the world," her mother said. "She had a lot of compassion for people."

After attending embassy schools, her recent transition to a public school was difficult, said Holt. To make it easier, and to get her away from Fossett, her mother enrolled her in a private school for the following fall and planned a summer trip for her out of the country.

Holt said she made plans to quit her job as a documentary producer, telling co-workers, "I have to leave work because I have to save my daughter's life," and arranged to change her daughter's seventh period at school to keep her from having to see Fossett at the end of the day.

In the weeks before her death, Summer was trying to break off with Fossett, and he threatened to kill her if she tried to leave him, Holt said. She got a part-time job at Baskin-Robbins ice-cream store and made new friends. "It was a step away from Marcus," said Holt.

But Fossett would pull her back again, and Holt said her fear grew. Holt said her daughter told her, "Mom, it's okay. I'm working it out."

No one is sure exactly what happened on May 7.

Fossett gave police investigator Thomas Lyons numerous versions of the shooting, saying at one point it was an accident and then calling it a suicide. He told the officer that he and Summer skipped school after first period, went to some woods behind the football field and talked, then went to his house, where they watched television, had sex and then watched more television.

They ended up in his father's bedroom, where police found her body with a bullet wound in her face.

Fossett's attorneys argued yesterday that their client had never been in trouble before and was "just a typical teenage boy" and "not a streetwise thug."

Fossett's teacher in the juvenile detention center testified that he writes of his love for Summer and talks about her -- always in the present tense.

In giving Fossett 22 years, Bach rejected that argument, saying, "In this case, the crime is just so bad." He will be eligible for parole in a little more than three years.