Colten Boushie's DNA was on a rifle barrel found near his body in Gerald Stanley's farmyard, a blood splatter analyst and expert witness has testified.

The detail came late Tuesday during the first day of testimony in the trial of Stanley, who is accused of second-degree murder in Boushie's August 2016 death.

Boushie and four others drove in an SUV onto the farmyard near Biggar, Sask., before the 22-year-old man was killed by a bullet in the head.

The RCMP analyst, Sgt. Jennifer Barnes, wrote a report on the blood splatter in the SUV several months after the shooting.

Barnes said her report was based on her examination of photos of the blood splatter in the grey Ford Escape. Boushie's body was ultimately found on the ground beside the SUV.

Scott Spencer, the lawyer for Gerald Stanley, leaves the Battleford, Sask., courtroom Tuesday after some aggressive questioning of RCMP members about their investigation into the death of Colten Boushie. (Jason Warick/CBC)

DNA found in blood samples swabbed inside the car matched DNA found on the rifle barrel, said Barnes.

Scott Spencer, Stanley's defence lawyer, questioned the wisdom of her not actually being at the scene.

"If you don't do an investigation, you can't form an opinion," he said.

Earlier, Spencer questioned other RCMP investigative methods and the police force's evidence collection.

Under cross-examination, the RCMP officer in charge of forensics at the scene, Cpl. Terry Heroux, said the SUV had not been preserved by the RCMP.

No blood splatter analysis after shooting

Heroux added that, beyond searching the inside of the car with a pure white light and taking some swabs, he not did order an intensive blood splatter analysis at that time.

"You're suggesting you're the ident guy who does the exam of the evidence, takes a swab and you don't care what happens?" said Spencer.

"That's the process," said Heroux.

A courtroom sketch shows RCMP Cpl. Terry Heroux testifying with the help of a board showing an aerial view of the Stanley property. (Cloudesley Rook-Hobbs)

Heroux said he did not know where the car was taken after it left the secure RCMP examination bay.

"Are you unaware of the obligation to provide the defence with the evidence so we can do independent testing?" asked a clearly rattled Spencer.

"We do our processes and then it's passed off to the lead investigator and the major crimes section," said Heroux.

Spencer offered only brief comments after court, saying it was good to start hearing evidence in the case.

Testimonies to be marked by 'contradictions'

In his opening argument Tuesday, Crown prosecutor Bill Burge said the three-week trial will be marked by "contradictions" in what people saw on the farm the evening Boushie was shot.

Stanley, 56, has pleaded not guilty to second-degree murder.

Burge said Stanley was working on a fence at his cattle farm near Biggar, Sask., when a car was heard loudly coming onto the property. Stanley's son, Sheldon Stanley, was also at the farm that day.

Stanley's son heard 3 gunshots, lawyer says

According to Burge's account, the car, a dirt-strewn 2003 Ford Escape SUV with a rim but no front tire, approached a truck that had been dropped off at the farm for Stanley to work on. Someone got out of the SUV and got into the truck.

The SUV then moved farther into the farmyard. Someone got out of the car and tried to start an ATV, which spurred Sheldon Stanley to yell at the people in the SUV, the prosecutor said.

The Stanley farm was photographed by CBC in August 2017, a year after the events that led to Boushie's death. (CBC)

The SUV collided with another vehicle on the property, said Burge.

He added that Sheldon Stanley said he heard two gunshots as he went into the farmhouse to get his own truck keys. As he left the farmhouse, he heard another shot.

Cpl. Terry Heroux, a forensic identification specialist with the RCMP, was the first Crown witness to testify.

Colten Boushie was killed on a farm near Biggar, Sask., in August 2016. (Facebook)

He presented crime scene photos showing Boushie's body face down — his feet by the driver's side of the Ford Escape. The photos were taken early on the morning of Aug. 10, a day after Boushie died.

The gravel road leading to the Stanley property is shown in August 2017. (CBC)

Boushie's mother, Debbie Baptiste, left the courtroom shortly before those photos were shown.

"I pity my sister that she has to see this," said Boushie's uncle, Alvin Baptiste. "Pretty graphic to see my nephew laying there and the blood splatter all over the vehicle like that."

The Crown prosecutor said two bullet cartridges were recovered from the yard.

A rifle barrel with five bullets in its magazine and one in its chamber was also found at the scene beside Boushie's body, Heroux told jurors. Boushie had been shot in the head, the bullet having entered behind his left ear, according to Burge.

The jury trial is taking place at the Battleford Court of Queen's Bench courthouse. (Guy Quenneville/CBC)

Spent and live ammunition for a 22-calibre rifle was also found in the grey Ford Escape.

In the Stanley farmyard, several spent bullet casings that were corroded were found near the deck leading into the house.

Rain during the days after Boushie's death washed blood from the SUV door and ground where Boushie's body lay covered by a tarp to protect against rain, said Burge.

When asked by Burge if anything had been done to protect the SUV against the rain, Heroux said only that the scene was cordoned off.

Boushie's DNA found on gun found in home

The Crown said Boushie's DNA was found on one of at least 11 firearms recovered from Stanley's home and property.

Two guns, including a Russian-made pistol, were found in a closet on the home's main floor, two long guns were found in a bedroom, and seven firearms, including long guns and pellet guns, were also found in a basement office.

Sheldon Stanley will testify later in the trial, in addition to other police officers and the four people who, alongside Boushie, drove onto the Stanley property that day, Burge said.