Ray Cantelo enters court on Dec. 10. (CBC)

Breathalyzer test results don't support what a Kings County man — accused of impaired driving causing death — told police about his drinking the day of a collision in Eastern P.E.I., a toxicolgist testified in Supreme Court Wednesday in Charlottetown.

Ray Cantelo, 73, failed two breathalyzer tests on October 22, 2011, about three hours after a collision in which Stacy Cheverie, 38, died and her husband, Bernard, was seriously injured. Their motorcycle collided with a van at the intersection of Peakes and St. Patricks roads.

On Tuesday, court watched videotape of a police interview taken at the time of Cantelo's arrest, in which he tells investigators he left the crash scene, went to his girlfriend's house and drank "three or four stiff drinks" to calm his nerves.

But Cantelo's alcohol readings are nearly double what they would be if he drank only after the crash, said RCMP forensic alcohol specialist Heather Marie Copley.

Cantelo's blood-alcohol readings showed 130 and 120 milligrams of alcohol per 100 millilitres of blood.

Copley, from the RCMP Forensic Laboratory in Halifax, said people are too physically impaired to drive when their blood-alcohol levels are 100 milligrams. She said impairment occurs at levels of 50 and 100, but varies from person to person. Hardened drinkers can consume more before becoming impaired.

The Crown prosecutor intends to build a case that Cantelo's blood-alcohol readings prove he was drinking far more than he admits, hours before the crash occurred.

Traffic expert on stand

RCMP traffic collision analyst, Const. Jeffery Dow, also testified Wednesday morning for the prosecution as an expert witness.

Dow told court the motorcycle, driven by Bernard Cheverie, was headed west on Peakes Road, travelling at about 80 km/h, which is the speed limit in that area.

He measured the motorcycle's skid mark at nearly 30 metres.

"I located a single tire brake mark I determined to be from the motorcycle," said Dow.

Dow testified damage to the front driver's side of the white Mazda minivan driven by Cantelo — a broken front fender turn-signal cover — was consistent with being hit by Cheverie's Yamaha motorcycle.

The motorcycle suffered extensive damage caused by sliding along the pavement, tumbling, then impacting with the van, said Dow.

But there was no way of knowing if Stacy Cheverie hit the van, said Dow. She could have been killed by hitting something else, such as the ground.

During cross-examination, defence lawyer Brenda Picard made the point that the stop sign is well back from the intersection and that would have required Cantelo to "nose forward" past the stop sign to get a good look both ways on Peakes Road in order to make a safe turn.

On re-examination by the Crown, Dow said there is good visibility at the intersection and Cantelo would have had a clear view of what was coming.

Cantelo has pleaded not guilty to impaired driving causing death, impaired driving causing bodily harm and failure to remain at the scene of an accident.

In testimony earlier this week, a witness to the crash testified she saw the motorcycle hit the van, and got out to try to help the victims.

She told the court the driver of the van got out and asked her whether anyone was hurt. She said yes, and that she was going to call 911. The woman testified the driver of the van then got back in his vehicle and drove away.