The RCMP officer took a couple steps back, away from the witness podium, as he demonstrated in court what he said Allan Potter did to him one night in a McDonald's parking lot in Ontario.
On Sept. 25, 2016 the men were on their way to a hotel in London, having just buried what Potter believed was a dead body inside a hockey bag. The Mountie was working undercover as Potter's new boss, the operator of a debt collection service, and Potter had been told the body in the bag - in reality, the carcass of a pig wrapped in sheets - was that of a man who had failed to pay the money he owed.
The undercover officer was wearing a hidden audio recording device, but it was Potter's alleged actions, illuminated by the light of a street lamp in the fast-food restaurant parking lot, that the Crown asked the Mountie to explain in the courtroom.
"This is the opportunity that I took, after dealing with the hockey bag at the cemetery, to revisit the topic of discussion that Mr. Potter and I had initially had in Minden, when he brought up the fact that he had been arrested for murder," the police officer testified.
He and Potter had met in the town of Minden earlier that day.
"It was clear to me that Mr. Potter was uncomfortable talking about this and certainly uncomfortable talking about this topic in the car."
Potter, 55, is on trial for the first-degree murder of 39-year-old Dale Porter in North River, Conception Bay North, in June 2014. A second man has also been charged and will go to trial at a later date. Potter was arrested and questioned by police in the days following Porter's death, but was not charged.
The undercover officer told the court Thursday that after he and Potter got out of the car to go into McDonald's, Potter began talking about the night Porter was killed.
"Mr. Potter is then explaining to me that Mr. Porter had disrespected the (Vikings Motorcycle Club) vest that was being worn that night," the officer said. "He was telling me that this night Mr. Porter had in fact been very disrespectful to the vest and that it didn't mean shit to Mr. Porter. Mr. Potter then proceeded to demonstrate to me stabbing Mr. Porter, giving me a physical demonstration in the McDonald's parking lot."
Mimicking the actions, the officer said Potter made a fist with his right hand, then pressed it into the front of the policeman's body in three different spots.
"Then Mr. Potter actually took his left hand on my left shoulder and spun me around, then pressed his same hand twice in my back. Thus, that was him demonstrating stabbing Mr. Porter," the RCMP corporal said.
Audio recorded from the officer's hidden device was played for the jury.
"I was protecting this guy, my brother," Potter's voice was heard saying. "And the guy was telling him, this don't mean shit to me and I'm gonna f--- your lady and I was there. I walked out. Really. Mmm, mmm, mmm, mmm, mmm, mmm, mmm, mmm! Ding, ding, ding, ding! Stood up and he grabbed it ... I just went right around, about that deep each time. He just took it all ... and then I kept walking. Closed it.
It was at the "Mmm" and "Ding" points that Potter had demonstrated the stabbing motion, the officer testified. He said while Potter had been saying "About that deep," he had been using his thumb and index finger to indicate a space of about three or four inches. The officer said he understood that as Potter indicating the depth of the stab wounds.
"And when he said 'Closed it,' what's he referring to then?" prosecutor Sheldon Steeves asked.
"He closed the knife, and then he indicated that he handed it to (the other man) who was with him," the Mountie replied.
There had been talk of the knife earlier in the car, the officer testified, when Potter had said, "I didn't see it go. He gave me his word that it was gone in the ocean."
Earlier in Potter's trial, one of two Vikings club members-turned paid police agents testified he had been with Shane Leonard, who was the club president at that point, when Leonard threw a black-handled knife the agent recognized as belonging to Potter into the ocean near Cape Spear. Another blade was seized by police and entered as evidence at Potter's trial: a folding knife with an eagle and a decorative blue stone on the handle, found in a roadside brook in Cupids by a member of the public. Investigators found no traces of fingerprints or DNA and its alleged connection to Porter's death is not yet clear.
The officer also told the court Potter had indicated the clothing he had been wearing the night Porter was killed had been burned, including a $500 jacket and his belt.
Earlier testimony from a DNA expert revealed forensic testing completed on a hoodie Potter had been wearing when he was arrested for questioning after Porter's death had located small blood-coloured spots containing Porter's DNA. Potter had also agreed to provide police with a sample of his own DNA in connection with the investigation.
"That was three years ago," Potter was heard saying to the undercover officer on the audio recording. "They've had that DNA for three f---ing years. They would have charged me by now."
Potter was arrested and charged with Porter's murder the next day.
At one point Thursday, defence lawyer Randy Piercey objected to the RCMP officer's testimony, saying the officer was presenting his own interpretation of the meaning of certain things he said Potter had done and said.
Earlier in the day, the jury heard audio recordings from the moment Potter, the RCMP corporal and two other undercover Mounties buried the hockey bag containing the "body," then used bleach to clean their hands and the soles of their shoes.
Back in the vehicle with the corporal, Potter was less talkative than he had been previously.
"That guy suffer?" he asks.
"No. I was thinking exactly the same thing," the officer replied.
"Talk about f---ing first days," Potter said later. "Damn, my first day (on the job). How's that for you?"
The officer, who is the final witness for Steeves and fellow prosecutor Erin Matthews, is expected to finish his testimony Friday, after which the case will be handed over to the defence.
Piercey and co-counsel Jon Noonan are expected to call only one witness to the stand: Potter.