The gun Benjamin Nason is accused of using to shoot Beth Ann Wallace on Jan. 29. (Susan King/CBC)

An expert at the attempted murder trial of Benjamin Nason testified Friday that spent bullet casings found at the scene came from Nason's gun and that the weapon did not discharge accidentally.

Nason, 38, of Beaver Dam, is accused of trying to kill his former lover Beth Ann Wallace, 40, who suffered a single gunshot wound to her upper body, outside her Lincoln Heights home on Jan. 29.

Joseph Prendergast, an RCMP ballistics expert, told the Court of Queen's Bench jury he examined the Browning 270-calibre bolt-action rifle seized from Nason's house.

He put the rifle through of serious of shock tests to see if it would somehow accidentally discharge, but found no problems, he said.

Prendergast also tested two spent bullet casings found at Wallace's home and confirmed they came from Nason's gun.

Earlier this week, Wallace testified that Nason had come to her home with a rifle and threatened to kill her during the early morning hours of Jan. 29.

She was shot in the back, near her shoulder, as she fled down her driveway to a neighbour's house.

Wallace has undergone seven surgeries to repair her arm, and still requires additional surgeries, the courtroom heard.

The Crown wrapped up its case on Friday. The defence is expected to begin presenting its case on Monday.

The trial, which began on Aug. 19, is scheduled to take about two weeks.