The remains of a whole body were not found in the livestock incinerator police discovered on Dellen Millard's farm, a forensic expert told a Hamilton court Thursday.

Forensic anthropologist Dr. Tracy Rogers testified in Superior Court that the lack of remains indicated to her that the incinerator, known as The Eliminator, had been cleaned out.

"There are a lot of remains that are not there," she told the jury, saying she was asked for help in May 2013 by Hamilton police officers who were investigating the disappearance of Tim Bosma, 32, of Ancaster, Ont.

"There should have been a complete body there basically, but there wasn't… So obviously, it had been cleaned out at some point."

Prosecutors told the jury during their opening address that the bones found in the incinerator belonged to Bosma, who they believe was burned after being shot and killed at close range inside a Dodge pickup truck he had been trying to sell online. Bosma was last seen on May 6, 2013, leaving his home with two men who wanted to test drive the vehicle.

Millard, 30, of Toronto, and co-accused Mark Smich, 28, of Oakville, Ont., have both pleaded not guilty to first-degree murder in Bosma's death.

I thought it was important for the family's peace of mind that they had all the remains back. - Dr. Tracy Rogers, forensic anthropologist

The largest bone that was found in the incinerator was a human left radius, which is a bone in the forearm, Rogers told the court.

"This bone is normally straight, but in this picture, it's quite curved. This is because of fire damage," Rogers said. "This bone had been exposed to fire — high temperature."

Bones badly damaged

The second, smaller bone found was a human metacarpal, which is a bone in the palm of the hand. Rogers testified she couldn't tell if it came from the left hand or right hand because it was so damaged.

The University of Toronto professor finished her testimony by telling the court how she vacuumed out the incinerator with a new machine to get any remaining small bone pieces.

"I thought it was important for the family's peace of mind that they had all the remains back," she said, her voice cracking.

That courtesy wasn't lost on family members sitting the courtroom.

Tim Bosma vanished after taking two men for a test drive of a truck he was trying to sell in May 2013. His burned remains were later found on a farm in Ayr, Ont. (Facebook)

Bosma's father, Hank, followed Rogers out of the courtroom when she was finished testifying and hugged her tightly just outside the doors.

In her testimony, Rogers said that the bone's joint surfaces helped verify that they were human. She said she could tell with 75 per cent accuracy that it was a man, and most likely under the age of 40.

Because humans stand upright, upper limbs aren't used for weight bearing like an animal's are, Rogers said. "So the joints in humans look very different than the joints in animals."

The curvature in bones is different in humans and animals too, which helped her determine the bones found in the incinerator were human.

"Most people think that when a body is burned it will disintegrate or totally turn to ash, but that's not what happens," Rogers said. Bones are mostly mineral, so when the water in the bones burns out, they warp, she testified. "It sometimes becomes fractured and cracked as the bone is drying out."

Experts spent days examining the livestock incinerator, where human bones were found. (Court exhibit)

Rogers was not cross-examined by either defence lawyer.

Court also heard from people who lived, worked and hunted on or near Millard's farm around the time that Bosma vanished.

Steve Henhoeffer, a dairy farmer, testified he saw smoke coming from the Millard farm around 6 a.m. when he was milking his cows a day or two after Bosma was reported missing.

"It was very odd that thick, black and grey smoke would be coming up," he said.

Incinerator appeared after May 5, witness says

Armin Seibert, who lives next to Millard's farm, told the court that he saw flashlight beams bouncing off the silo at the back of his barn around 11 p.m. or 11:30 p.m. on May 7 or May 8, 2013.

Court also heard from Jason McGrath, who had an arrangement to hunt turkey and deer on the farmland. He testified that he was on the property on May 4 and 5 near where the incinerator was later found. But when he was there, he did not see the machine.

In cross-examination, Millard's lawyer, Nadir Sachak, asked McGrath if he was ever told to get off the property.

"All the times you went hunting, nobody ever interfered with your ability to hunt?" Sachak asked. "No," McGrath replied.

CBC reporter Adam Carter is in the courtroom each day reporting live on the trial. You can view a full recap of his live blog here:

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adam.carter@cbc.ca