An Arlington County judge yesterday sentenced GOP activist and lawyer Kevin Sabo to 18 months in prison for cutting the brake lines on his ex-girlfriend's car last March, causing her to crash into a fence to avoid barreling into a busy intersection.

Circuit Court Judge Joanne F. Alper imposed the sentence recommended by a jury in December, noting the terror the victim felt when she realized she had no brakes and "the extraordinary danger this incident posed" to other motorists.

"The jury, after all, is the conscience of the community," Alper said. "That is their statement of the seriousness of the crime."

Sabo was convicted of attempting to maliciously wound Heather Lawrence, 28. The sentencing range available to the jury ran from a fine to 10 years in prison. In Virginia, judges can decrease, but not increase, a jury's sentence. Virginia is one of only a few states in which juries recommend sentences.

Sabo's attorney, A. Strode Brent Jr., asked Alper to suspend at least part of the 18-month sentence. If Sabo, 38, had been convicted without a jury, Brent said, the sentencing guidelines would have called for no prison time. A minister at Sabo's church, United Methodist Church in Annandale, testified that he would serve as Sabo's spiritual adviser and challenge him to rebuild his life.

But Alper noted that sentencing guidelines are strictly voluntary. And she agreed with Deputy Commonwealth's Attorney Theo Stamos that cutting someone's brakes was a "quite unusual" crime that did not easily fit into any sentencing category.

The jury clearly believed that Sabo, a lawyer, had raised his right hand, sworn to tell the truth and then lied on the witness stand, the judge said.

Calling it a "very tragic case," the judge noted that Sabo was not a typical defendant and that he had squandered many opportunities, including the possibility of elective office, by his actions on March 17. Sabo has resigned his positions as GOP chairman in Northern Virginia's 11th Congressional District and as a member of the Virginia Commonwealth Transportation Board.

That morning, Lawrence was driving to work on Brookside Drive in Arlington when she realized her brakes were gone. Just before entering Brookside's busy intersection with Washington Boulevard, she was able to crash her 1997 Volkswagen Jetta into a fence. She was not injured.

Stamos argued during the trial that Sabo had cut the brakes because he was upset over the breakup of his eight-month relationship with Lawrence the day before. The two began dating when both worked at a lobbying firm in the District and he was still married.

Sabo testified at the trial that he was making up a story when he told Lawrence during a lengthy, tape-recorded phone conversation that he had "done something" to her car. He said he made that up because she was pressuring him for an explanation and he feared that she would otherwise tell his wife about their affair and damage his relationship with his young daughter.

"I have to start all over," Sabo told the judge, noting that he has devoted years of his life to public service. "I'm not the type of individual likely to be before" the court again.

After the hearing, Brent said Sabo still denies cutting the brakes and plans to appeal the conviction.