An Antigonish, N.S., man has been found guilty of impaired driving by drugs and causing the death of two teens in what may be the first conviction of its kind in Canada.

William Lionel Edmund Byron Fogarty, 30, was driving a car that collided with another vehicle on Highway 4 in Antigonish County in November 2011. The two teens in the other car, Kory Mattie, 16, and Nicholas (Nico) Landry, 17, died following the crash.

Fogarty was driving a Crown Victoria and the teens were in a Ford Mustang driven by Mattie when the head-on collision occurred on on a clear November afternoon.

Fogarty had methadone, several prescription drugs and Valium in his system when his car crossed the centre line on the two-lane road.

During the trial, two witnesses testified they called the police to report Fogarty's erratic driving just before the crash. Carl Delorey said Fogarty was crossing the centre line and veering onto the shoulder.

Fogarty was found guilty on all charges against him: two counts of dangerous driving causing death and two counts of impaired driving by drugs causing death.

Families relieved

In Antigonish Wednesday, Landry's father, Doug McKenna, said he was happy to hear the verdict after many sleepless nights.

"I'm glad it's over," he said. "The justice system did its job, and I believed in them."

McKenna now wears a button with his son's photo on it as a reminder.

"At least the guy was convicted, but it doesn't bring my son back at all."

Landry's mother, Jeannie Landry, was tearful as she expressed relief at hearing the verdict.

"We got what we wanted and he's off the streets," she said of Fogarty. "You try to pick up the pieces and go on, I guess, now. We'll never have the boys back, but at least we know it wasn't their fault. They did the best they could."

September sentencing

Fogarty will be sentenced in September. Both the Crown and defence said they believe he’ll get federal time, which is more than two years in prison.

Crown attorney Darlene Oko said the maximum sentence for impaired driving by drugs causing death is a life sentence.

Oko wouldn't say what the Crown will be asking for.

"We want to digest the decision first and consider it before we put a number on it," she said. "These are very serious offences."

Crown attorney Allen Murray said the case was unique because it covered new sections of the Criminal Code which address being impaired by drugs.

"This is, perhaps, one of the first cases of this nature in the country," he said.

Fogarty offered no comment as he left the courthouse in custody.