HALIFAX – A defence lawyer appeared to suggest Tuesday that an off-duty police officer died accidentally during a consensual sexual encounter inside a Halifax apartment after encouraging Christopher Garnier to choke her.Dr. Matthew Bowes, Nova Scotia’s chief medical examiner, told Garnier’s second-degree murder trial that Catherine Campbell died of strangulation, and suffered head injuries including black eyes and a fractured nose.Bowes said her body was found face down and partially decomposed.Under cross examination, defence lawyer Joel Pink asked Bowes about “erotic asphyxiation” and presented a hypothetical scenario, describing a sexual encounter between “Mr. A and Ms. B.”Pink suggested Ms. B had a fantasy about being dominated and while they were kissing in the hallway of the apartment, she told Mr. A to choke her.“Assume in the hallway, Mr. A put his right hand on Ms. B’s neck and Ms. B told Mr. A not to worry. Assume further that Ms. B asked Mr. A to squeeze harder,” Pink said to Bowes.Pink suggested Mr. A then led Ms. B down the hallway to a pullout couch.“Assume that Mr. A applied pressure with his right forearm to the left side of the neck while his elbow was on the mattress,” said Pink.“Ms. B then told Mr. A to slap her and Mr. A did. Ms. B pressured Mr. A’s right arm to apply more pressure to her neck. Assume at no time did Ms. B resist the actions of Mr. A.”Pink added: “Assume further Mr. A noticed blood coming from Ms. B’s nose area. Assume further that Mr. A went to retrieve a towel and when he returned he found Ms. B completely still. Ms. B had stopped breathing.”Pink asked Bowes if the hypothetical scenario would fall into the category of erotic asphyxiation — or breath play, he said — and he agreed, conceding the possibilities in the hypothetical could not be excluded.But Bowes said he did not consider erotic asphyxiation when doing his autopsy, which concluded Campbell had died of strangulation.A member of Campbell’s family stormed out of the courtroom during Pink’s cross-examination of Bowes.The Crown has alleged Garnier punched and strangled the 36-year-old Truro, N.S., police officer inside a McCully Street apartment and used a green compost bin to dump the body in thick brush near Halifax’s Macdonald Bridge.The 29-year-old man, who met Campbell at a Halifax bar, has pleaded not guilty to second-degree murder and interfering with a dead body.Bowes said under cross-examination that injuries including her black eyes and broken nose could have been caused after death. But he earlier noted that he concluded the head trauma likely happened “either just around or right before death.”Earlier Tuesday, the jury was shown images of the body, which was found on a steep embankment near the bridge.Halifax police Sgt. Tony Croft said he took videos and photos of the scene off Valour Way in the early hours of Sept. 16, 2015, five days after the Crown alleges Garnier killed Campbell.The jury was again shown video of the body found in brush under a box, and was also shown photos of tattoos on the body.Croft also described photos he took of a compost bin that was found in a wooded area nearby at the end of a ramp that leads from North Street to Barrington Street.He said he later went to an RCMP detachment to photograph Garnier after his arrest.The trial also heard from two officers who conducted surveillance on Garnier the evening of Sept. 15, 2015, and into the following day, and that he was spotted driving in the area where Campbell’s body was found.Follow (at)Aly Thomson on Twitter.