SAINT JOHN, N.B. -- The lead investigator into the murder of Richard Oland says there was never any evidence that Dennis Oland owned or was in possession of a drywall hammer, which was the suspected type of weapon used to kill the Saint John, N.B., businessman on July 6, 2011.

Last week, Const. Stephen Davidson said a drywall hammer or similar instrument was suggested as the possible murder weapon, although no weapon has ever been found.

On Tuesday, under questioning from defence lawyer Gary Miller, Davidson said investigators discussed the possible weapon following the autopsy and the report of forensic identification officer, Sgt. Mark Smith.

Davidson said he used the online search engine Google to look up pictures of the tool, which commonly features a hammer head and a sharp blade-like surface.

Davidson also said he made inquiries at hardware stores about drywall hammers but never purchased any.

"There are many kinds," Davidson said.

The body of Richard Oland was found face down in a pool of blood in his Canterbury Street office on July 7, 2011.

He had suffered about 40 blunt and blade-like injuries to his head and neck.

Miller asked Davidson if he had any evidence that Dennis Oland ever owned or was in possession of a drywall hammer.

Davidson said "No."

He also confirmed that it was never suggested to the pathologist or other experts that a drywall hammer was the possible weapon.

Much of the day consisted of more grainy video being used by the defence to raise questions about the timeline of events on the day Richard Oland was killed.

Miller played a series of video segments from different cameras to illustrate where Dennis Oland parked his car when he visited Richard Oland on July 6, 2011.

Dennis Oland is the last known person to see his father alive, and has pleaded not guilty to second-degree murder.

Some of the video is quite blurry.

On Monday, a forensic video expert said despite what is suggested by TV shows and movies, it is not possible to improve the resolution of blurry video.

Miller showed video clips of a man and a woman shopping at Kennebecasis Drugs and Cochran's Market in Rothesay at 7:38 p.m. on July 6, 2011.

Davidson agreed that Dennis Oland said during his interview with police that's where he and his wife were that evening.

An earlier witness had identified Oland and his wife in the Cochran's video.

Miller then asked Davidson, "If John Ainsworth and Anthony Shaw (who were working at Printing Plus, below Richard Oland's office) heard noises between 7:30 and 8 p.m., and the noises were the killing of Richard Oland, then Dennis Oland couldn't have done it?"

Crown Prosecutor P.J. Veniot immediately objected.

Justice John Walsh sustained the objection.

"That's not a proper question," he said.

"That's up to the jury to decide."

Justice Walsh took time to give what he called his mid-trial instruction to the jury on how it needs to consider video and image evidence.

He said it is up to the jury members to decide what the images show or don't show and how much weight to give them during their deliberations.