A 19-year-old youth convicted last month in the deaths of four persons in an auto crash in Annandale was sentenced yesterday to two years in prison by a judge who angrily called him "an irresponsible, undisciplined scofflaw" after learning he had 17 prior driving offenses.

"Maybe these deaths could have been avoided . . . if you hadn't been given so many breaks," Fairfax Circuit Court Judge F. Bach told Jonathan Peter Reinemer, who could have been sentenced to up to 20 years in prison for his conviction of involuntary manslaughter. The two-car, head-on collison last Nov. 9 killed Reinemer's three passengers and the driver of a second car.

"You're not like so many people in the ghetto who never had a chance. You were given every chance and you've never taken advantage of it," Bach told the Falls Church youth.

He sentenced Reinemer to 12 years in prison but suspended 10 years. He also revoked Reinemer's driver's license for 10 years and ordered him to enter an in-patient alcohol treatment program and perform 2,000 hours of community service at the Northern Virginia Training Center for the handicapped after his release from prison. Reinemer will be eligible for parole after serving six months in prison.

"My initial impression of your case was that you were an unfortunate kid who had one too many beers at a party and found himself in the middle of a terrible tragedy," a grim-faced Bach said.

"But after the presentence report I formed a little different impression," said Bach to a tense, silent courtroom overflowing with relatives of the crash victims and friends and family of Reinemer, whom the judge convicted after a two-day, non-jury trial.

Included in the presentence investigation was a report of Reinemer's most recent arrest on a misdemeanor charge of drinking in public. That incident occurred last month in Dranesville District Park, 10 days before the start of his manslaughter trial, when a Fairfax police officer discovered Reinemer and eight other youths drinking beer and smoking marijuana. Also included in the report is a list of Reinemer's 17 prior driving offenses, including driving while intoxicated, racing on the highway and reckless driving.

When the judge asked whether he had anything to say before being sentenced, Reinemer, clad in blue jail fatigues, his hands folded in front of him, responded: "I realize what I did was totally inexcusable." His attorney, Robert Hall, asked Bach, "Can you bring back four dead people with a penitentiary term?" The judge rejected Hall's request that the youth make restitution by working at Fairfax Hospital instead of going to prison.

After the sentencing, Reinemer's mother, who sat in the front row during the 90-minute hearing, walked into the hallway outside the courtroom and collapsed weeping into a friend's arms. She said she was not surprised by the sentence, but declined further comment. Her son plans to appeal his conviction.

"I'm just glad he didn't get off," said Edward R. O'Brien, the father of Lawrence O'Brien, the 23-year-old fatally injured driver of the star struck by Reinemer, who skidded out of control as he was rounding a curve on Annandale Road returning from a beer party. "I couldn't believe he was out drinking and smoking pot with this hanging over his head."

In a two-page typed statement he gave to reporters, O'Brien said that shortly after Reinemer's conviction he called the youth's parents and offered to make a statement to the judge on this son's behalf.

"I felt that young Reinemer deserved every benefit of the doubt and possibly a second chance," wrote O'Brien. "But when I viewed his past driving record I was absolutely and utterly appalled.

"I retract all trace of anything remotely sympathetic," he continued. "I do not blame him quite so much as I now blame The System and his parents . . . [the former for] allowing such a menace as this to remain on the road . . . and his parents for not exercising the needed parental control earlier."

The accident, which Bach last month attributed to Reinemer's excessive drinking, speeding and reckless driving, resulted in a wrenching case of mistaken identity when two badly disfigured crash victims, one dead and the other alive, were confused by hospital officials for two days before grieving family members were informed of the error.

Defense attorney Hall yesterday called several defense witnesses in an attempt to show that Reinemer was grief-striken by the accident. They included a nurse at Fairfax Hospital who testified that the youth cried frequently and once sad he wished he had died instead of his friends.

"Words are cheap, it's conduct that counts," said prosecutor Stephen A. Merril, who argued that Reinemer should receive a five-year prison sentence. "This accident was as inevitable as the sun coming up in the morning. This was a tragedy that was bound to happen."