03/03/2016 12:08 EST | Updated 03/04/2017 00:12 EST

Tim Bosma trial: Bullet casing found in truck dominates testimony

The location of a spent bullet casing that was found inside Tim Bosma's truck dominated the morning session at the trial of two men accused of killing the Hamilton man.

Retired Ontario Provincial Police identification officer David Banks returned to the witness box to continue his testimony.

Dellen Millard, 30, of Toronto, and Mark Smich, 28, of Oakville, are accused of killing Bosma, 32, who lived in the suburban Ancaster area of Hamilton. Both accused have pleaded not guilty to first-degree murder in Ontario Superior Court.

Bosma disappeared in May 2013 after leaving his home to take two men on a test drive of a pickup truck he was trying to sell. More than a week later, police announced he was dead.

A line from Banks's forensic identification report read that a "spent firearm shell case was located on the rear passenger floor of the vehicle." Investigators didn't initially see it, and court has heard the theory that it was dislodged as the truck was being examined.

In cross-examination, Smich's lawyer Thomas Dungey suggested that the shell casing could have come from any part of the vehicle. The jury has not heard from any expert as to where a gun was fired in the truck. The Crown said in its opening address that Bosma was shot inside his truck.

Dungey said "all kinds of actions" happened with the truck — it was moved from Millard's mother's driveway to Hamilton, and then to an OPP facility in Tillsonburg, Ont. On the way to Tillsonburg, the truck's back doors accidentally opened up.

"That could easily cause a casing to flip back?" Dungey asked. "Yes, it could," Banks responded.

The truck was also removed from the trailer by a tow truck onto a flat-bed truck, because it was jammed in tightly, court has heard. "Pulling it back onto the flat bed could cause considerable jerking," Dungey said.

"It could flip back, because of jolts."

Bullet would 'have to negotiate a crater'

In his cross-examination, Millard's lawyer, Nadir Sachak, suggested the opposite, and outlined the various ways in which it would be difficult for anything to roll from the front to the back of the truck's cab, because parts of it had been stripped.

"There appears to be an obstacle in the rear portion of the cab," Sachak said. "There's this crater or indentation, and this wall or ledge."

If an object, be it a "tennis ball or a golf ball or a spent shell casing" was to roll down from the front, it would have to crawl up a ledge, Sachak said.

"It would have to negotiate that," Banks testified.

"It would have to negotiate a crater," Sachak said.

For the first time Thursday, the jury also saw photos of a charred corn husk that was found stuck in the burned out front seat that was recovered from the same trailer as Bosma's truck.

The front seats had been removed from Bosma's truck. The jury has previously heard there were two burn sites in a corn field on Millard's Ayr, Ont., farm, where The Eliminator livestock incinerator was also found.

Bloodstain pattern expert testifies

Waterloo police Sgt. Robert Jones testified Thursday afternoon about bloodstains found during the investigation.

He first focused on a green tarp that was found inside the trailer with Bosma's truck on which blood was detected. Court previously heard DNA analysis showed there is a one in 18 quadrillion chance that the blood found inside and outside Bosma's truck came from anyone other than him.

Jones said that he found "spattered" and "altered" stains.

A "spattered" stain occurs when blood is dispersed due to force, while an "altered" stain has had something happen to it.

"Can altered stains be produced on an attempt to clean blood?" assistant prosecutor Tony Leitch asked during his examination. "That's correct," Jones said.

Jones said that given the number of altered stains he saw, he believes someone tried to clean up the blood.