Daniel Tschetter, right, leaves the Calgary courthouse on Thursday after being convicted of manslaughter in a deadly December 2007 crash. (CBC)

A Calgary-area truck driver has been found guilty of manslaughter in the deaths of two adults and three children in a rear-end collision.

Daniel Tschetter, 51, was convicted Thursday afternoon of five counts of manslaughter and one count of obstruction of justice in the deadly December 2007 crash. Provincial court Judge Bruce Fraser stayed the five counts of criminal negligence, because that charge is similar to manslaughter.

During the trial, provincial court heard that Tschetter was speeding in his concrete-mixer truck, passing on the shoulder of Highway 2 and driving erratically before the crash.

Witnesses testified that they saw no brake lights when the truck plowed into the back of a car waiting at a red light at the intersection of 194th Avenue and Macleod Trail S.E., dragging it about 275 metres. The car ended up lodged under the bigger vehicle.

Kiarra Gautreau, 6, and Alexia Gautreau, 9, above, and Zachary Morrison, 16 months, below, died in the crash in December 2007. (CBC)

The occupants of the car — Chris Gautreau, 41; his daughters, Alexia, 9, and Kiarra, 6; Gautreau's fiancée, Melaina Hovdebo, 33; and her son, Zachary Morrison, 16 months — were killed.

Lee Morrison, Zachary's father, was crying and shaking as the judge described the details of the collision. Fraser said the accused knew he was approaching city limits and an intersection he had driven through "over 100 times," and yet continued to drive the same aggresive and dangerous manner, demonstrating a "wanton and/or reckless disregard for the lives or safety of others."

The judge said he accepted evidence Tschetter could have been driving as fast as 120 km/h at the time of the crash in "no ordinary automobile."

"It is a cement truck. It is 10 times the size and strength and weight of the average vehicle on the road. Most other vehicles are at its mercy if it runs them down," Fraser said in his decision.

Tschetter showed little emotion during the judge's decision, except for occasionally rubbing his eyes. His daughter sobbed in the courtroom when the manslaughter conviction was read out. There is no minimum sentence for manslaughter under the Criminal Code; sentences can range from probation to life in prison.

Driver testified he was distracted

Tschetter, who testified during the trial that he was a recovering alcoholic, said he was in a rush to wash out his truck after a cement delivery. He told the court he was distracted by checking on the vehicle's gauges and was frustrated because his water lines were freezing.

'People often say will it give you closure? No.'—Lee Morrison, victim's father

After the collision, Tschetter said he reached under his seat and took a drink of what he thought was water from a bottle, before realizing it was vodka.

He testified that he threw the bottle of vodka into the drum of his cement truck, because he didn't know what to do if people saw him with the container. Tschetter explained the vodka bottle was in the truck so he could offer drinks to staff at concrete suppliers to get to the front of long lineups."

Fraser said he did not accept Tschetter's explanation that he didn't know what bottle he was drinking from, but the judge was satisfied Tschetter's ability to operate a vehicle was not impaired by alcohol.

Instead, the judge pointed out Tschetter's state of mind "which appears to have affected his driving," and his conduct on the road that increased the risk of bodily harm or death.

Long sentencing hearing expected

Crown prosecutor Jonathan Hak said Thursday he expects the sentencing hearing, set for Aug. 5, to be lengthy, as many family members of the victims will want to give impact statements.

"People often say will it give you closure? No," Morrison told CBC News on Wednesday before the verdict. "I'm hoping that beautiful little face will somehow register with people that we lost our kids over a needless, senseless situation."

Herb Grieder, Zachary's uncle, quit his job to be at the courthouse for every proceeding before and during the judge-only trial.

"Emotionally and physically draining … but it was something I felt I had to do," he said.

Tschetter is free until his sentencing. Defence lawyer Balfour Der told the judge he intends on applying for a conditional sentence.

With files from Tara Fedun and Elizabeth Snaddon