A 26-year-old construction worker was convicted yesterday of three counts of involuntary manslaughter for killing three members of a family when he plowed into their car head-on while driving on the wrong side of a Fairfax County highway in April.

Juan Landeros, of the 2800 block of Joseph Makell Court in Alexandria, was sentenced to 12 months in jail and ordered to pay $1,000 in fines for each of the three counts. Fairfax County Circuit Court Judge F. Bruce Bach ordered the jail terms to be served consecutively.

The maximum sentence for each count is 10 years in prison. Landeros could be released from jail in 24 months, his lawyer said.

Landeros, who used crutches and wore a back brace from the broken back and ankle he suffered during the accident, bowed his head and wiped his eyes after the verdicts were read.

Relatives of the crash victims said they were not pleased with the jury's sentence. "I'm kind of disappointed," said Joseph L. Rastatter, son of victims Joseph A. Rastatter, 58, and his wife Mabel, 54, both of Dale City. The elder Rastatter's mother, Esther B. Rastatter, 84, of Erie, Pa., also died in the accident.

"I guess the people of Virginia are happy," Rastatter said. "They're the ones that are going to drive on the roads with him."

Assistant Commonwealth's Attorney Raymond Brownelle said he thought the sentence "was pretty light, to tell you the truth. The way in which he drove his car into those people. Three innocent people were killed."

According to witnesses, Landeros had driven a friend home the night of April 7 in the friend's blue 1979 Mercury Marquis because the friend was too drunk to drive. The morning of April 8 Landeros asked another man, Jens Petersen, to drive with him to return the friend's car.

As Landeros approached Belvoir Road southbound on Route 1, he ran into the back of Petersen's car, causing it to hit the car in front of it, Petersen testified. Landeros hit another car and then sped away at a high speed, witnesses said. The speed limit is 35 miles per hour at that point along the four-lane highway.

Other witnesses testified that Landeros raced on Route 1 and twice overtook cars by crossing the double yellow lines. Shortly thereafter Landeros smashed the Rastatter's white Nissan Sentra head-on, Brownelle said.

Brownelle suggested during his questioning of Landeros that he had raced away from the first accident because he was driving with a suspended license.

But Landeros said he didn't know his license was suspended. He testified that after hitting Petersen's car he was "scared and in shock" and that his brakes failed. "By that time I just lost control of myself," Landeros said.

Landeros testified that he turned off the car to stop it, but the steering locked, forcing him to drive into the Rastatter's car.

However, police said the brakes were adequate to stop the car. Officers also testified that there was no indication Landeros had turned off the car to try to stop it.

There was no evidence that Landeros had been drinking or using drugs, police said.

Landeros also was charged with two misdemeanor counts of hit and run and one count of driving with a suspended license. Those trials are scheduled for July 17.