Metro/Graham Lanktree OPP Cst. Shawn Kelly leaves the Ottawa court house where his expertise as an "accident reconstructionist" is being weighed by a judge.

After he was accused of destroying evidence Thursday, the OPP expert now at the centre of the trial of a Pembroke dentist charged with impaired driving causing death came under fire again Friday.

“Think carefully about what you’re trying to say constable. I’m not going to do anyone’s work,” Judge Neil Kozloff told OPP technical collision investigator Cst. Shawn Kelly as he was questioned about discrepancies in his testimony and final report.

Throughout the trial, Kelly has maintained that the SUV driven by Dr. Christy Natsis veered into the eastbound lane of the 417 near Arnprior, striking a pick-up truck driven by Ottawan Brian Casey and killing the man.  However, Kelly’s report on the Mar. 31, 2011, accident indicates that Natsis’ vehicle was in the westbound lane.

“Are you trying to say ‘I made a mistake by putting Westbound’?” Kozloff asked Kelly. “You really think, based on your evidence, that the Black Ford Expedition was in the westbound lane one second prior to impact?”

“No, I do not think that, sir,” Kelly answered, indicating the report was in error and that he sticks by his original testimony. Based on the gouges in the road and a trail of debris in the eastbound lane, has said the accident must have happened in the eastbound lane.

The case was expected to take four weeks. It’s now in it’s sixth week with no end in sight.

Kelly revealed in his testimony that black box-like devices taken from each vehicle indicate that Casey braked from 80 km/h to 30 km/h two seconds before that crash and that Natsis’ SUV continued its average speed of 86 km/h.

Natsis is also charged with dangerous driving and having over 80 mg of alcohol in her bloodstream. The defence moved to have all of Kelly’s testimony excluded from the trial Thursday.

The case is set to resume for seven days April 15.

More from Ottawa :