HALIFAX -- A Halifax murder trial was shown a video Thursday of a man rolling a compost bin that was allegedly used to dump an off-duty police officer's body after she was strangled.

The Crown has alleged Christopher Garnier killed Truro police Const. Catherine Campbell at an apartment on McCully Street in the early hours of Sept. 11, 2015, and used a green bin to dispose of her body near Halifax's Macdonald Bridge.

RCMP Sgt. Charla Keddy told the jury Thursday that she reviewed surveillance footage from a business near the apartment, where the jury has heard Garnier was staying with a friend.

She said the video from the parking lot of Soma Vein and Laser on Agricola Street shows a man leaving from the area of the backyard of the apartment shortly before 5 a.m.

"You see him returning, dragging a green bin, walking towards the back of the (McCully Street apartment)," said Keddy.

Keddy said the blurry figure in shorts and a T-shirt is then seen pulling the compost bin away from the same area a few minutes later, rolling it down a driveway and across Agricola Street towards North Street.

Keddy added the person also appears to bend down in the driveway, pick something up and throw it onto the roof of a building next door. A previous witness testified to finding a silver jewelry chain on the roof of a business on Agricola Street.

She also described seeing what she believed to be a mattress in the area of the McCully Street backyard in the video.

Members of Campbell's family wiped away tears as the jury was shown the video.

Keddy never identified the person in the video as Garnier.

The 29-year-old man has pleaded not guilty to second-degree murder and interfering with a dead body.

Earlier Thursday, a detective testified he saw what he suspected to be blood droplets in the McCully Street apartment.

Halifax Regional Police Det. Const. Marshall Hewitt said he photographed apparent blood droplets on surfaces including the floor, wall and baseboard.

The Nova Scotia Supreme Court jury was shown more than 150 photographs of various angles of the flat, which police had obtained a warrant to search.

Previous witnesses have testified Garnier and Campbell met at the downtown Halifax Alehouse early that morning before leaving at around 3:30 a.m.

A cab driver testified Thursday he sensed "tension" between a man and a woman he picked up in downtown Halifax early that morning and drove to McCully Street.

Cab driver Simon Zakarias told the jury the pair -- it was never established during his testimony that they were specifically Garnier and Campbell -- flagged him down.

"I felt a tension," said Zakarias, adding that he deducted this based on his experience driving cabs.

Under cross examination by defence lawyer Joel Pink, Zakarias conceded he could not hear what the two were saying to each other, so could not say for sure whether there was tension between them.

The jury also heard from Shaun Kenney, who worked as a warehouse manager at K & D Pratt Group Inc., an equipment distribution company.

Kenney testified that Garnier had been hired to work in the company's sales department and his first day of work was Sept. 14, 2015. He also worked the following day, and both days he appeared "professional" and "confident," said Kenney.

He did not report to work on Sept. 16, 2015. The jury previously heard Garnier was arrested by police the previous day after he was allegedly observed driving by the area where Campbell's body was dumped and not found for days.

Crown attorney Carla Ball said in her opening statement Tuesday that the case is "about a man who loses control."