HALIFAX -- An off-duty police officer was seen kissing and embracing Christopher Garnier at a downtown Halifax bar hours before he allegedly strangled her, a jury heard Wednesday.

RCMP Const. Kyle Doane told Garnier's murder trial Wednesday that he reviewed surveillance footage from the Halifax Alehouse after it was discovered Truro police Const. Catherine Campbell may have been dropped off there on Sept. 11, 2015.

Doane identified the 36-year-old Campbell on the video as a woman in a dress with a black belt around her waist who enters the bar shortly after 1 a.m.

Campbell arrived by herself and "had interactions throughout the evening with several males inside the bar," said Doane.

He said eventually Campbell and Garnier are seen on video kissing, embracing and dancing on the bar's upstairs floor.

"At one point they became quite passionate," Doane said just before the Nova Scotia Supreme Court jury was shown the video footage.

"The thing that stuck out the most was the point where her legs were wrapped around Mr. Garnier."

Doane said the pair are later seen on surveillance video leaving the bar around 3:30 a.m.

The 29-year-old Garnier is accused of second-degree murder and interfering with a dead body. He has pleaded not guilty to both charges.

The Crown alleges Garnier punched and strangled Campbell and used a green compost bin to dispose of her body in the area of Halifax's Macdonald Bridge, where it was found days later. Crown attorney Carla Ball said in her opening statement Tuesday that it was a case "about a man who loses control."

Garnier, wearing a black suit jacket, sat quietly at a bench with his lawyer Joel Pink as witnesses testified, his family sitting in the gallery behind him. Members of Campbell's family were also in the gallery.

The jury also heard Wednesday from a former head doorman at the Halifax Alehouse. Bradley Randall said he was working that night and saw Garnier, who he knew as a former co-worker at the bar.

Randall, 31, said he saw Garnier talking with a petite blonde woman at a table on the lower level of the bar for about an hour, and they eventually moved to the upper floor. When they came back downstairs, the pair were "a lot closer."

"She's standing between his legs ... as they talk. They start kissing, making out. Eventually she's sitting on his lap," Randall told the jury.

"A few times I had to actually tell them, 'You're in a public place. Calm down a little'."

Randall testified that neither Garnier nor Campbell appeared intoxicated.

Later Wednesday, Halifax Regional Police Det. Const. Scott MacLeod testified that he interviewed a friend Garnier had been staying with on Sept. 15, 2015, and learned a mattress from a pullout sofa and sheets were missing from the apartment.

"I observed in the hallway of the residence what I believed to be a single droplet of blood," said MacLeod.

He also said that he checked the roof of a nearby business, and that a silver jewelry chain was found. The jury was shown photos of the chain.

Mitchell Devoe, whom Garnier was staying with, said his friend had come over on Sept. 10, 2015, after a break-up with his girlfriend. They drank alcohol, smoked cannabis and eventually went downtown, said Devoe. He also made up a pull-out couch for him to sleep on.

Devoe said he remembers being at the downtown bar Cheers, but does not remember anything else after that. He woke up in the drunk tank at a police station and was released around 9 a.m. on Sept. 11, 2015.

Devoe said when he arrived home, Garnier was asleep on the sectional couch and he noticed the pull-out couch was folded away.

He later noticed the mattress was missing and asked Garnier in a text message what happened to it, and Garnier replied that he had vomited on it so he threw it out and was ordering him a new one. The jury was shown screenshots of their conversation.

Devoe said he was questioned by police on Sept. 15, 2015, and afterwards went to see Garnier at his workplace, and they had a 10-minute conversation inside Devoe's vehicle.

He told Garnier the officer had asked him about the mattress, but he said Garnier "kind of just laughed it off."

Devoe was also shown photos from inside his apartment, including a tray that was damaged.

Under cross-examination by Pink, Devoe said he did not notice any blood in his apartment. He also asked if the tray could have been damaged from a party he had a few weeks prior, and Devoe said it was possible.

The Crown has said it expects to call around 40 witnesses over the five-week trial, which resumes Thursday.