Sarah Nicole Rae was found fatally stabbed in a northeast Calgary home in August 2008. ((Calgary Police Service))

The final moments of Sarah Rae's life were on display in a Calgary court as a cellphone video showed her lying on a bed, the accused killer's camera slowly focusing in on the spreading red stab wound on her chest.

"This was the worst content I've had to see in 15 years of policing," said Const. Shafik Punja, testifying Thursday at the second-degree murder trial of Travis Martel.

Martel, 36, is accused of killing Rae, his girlfriend, on Aug. 3, 2008.

Punja, a computer forensics examiner, found the video on a deleted file on Martel's cellphone and was able to play it using special software.

With heavy-metal music blaring in the background, Rae is seen lying limply on a bed, moaning, appearing on the edge of unconsciousness.

The grainy two-minute video zooms in and out about 10 seconds into the recording. At the 33-second mark, the camera operator walks up to the victim and focuses on the wound.

A man's voice can be heard muttering from behind the camera of the Sony Ericsson flip phone.

"Good that I said I love you," says the voice, then adding, "This sucks. I'll be there soon with you, baby girl."

Members of Rae's family were warned by the Crown prosecutor and left the room when the video was about to be played.

Martel originally told police he had gone for a walk on the night of Rae's death and returned home to find her dead in his bed. He later insisted that the stabbing was an accident, triggered when she attacked him with a knife.

Martel called 911 at 4:59 a.m., saying his "wife" was dead in the bedroom with a large stab wound in her chest.

Accused said victim picked up knife

The judge-only trial also heard a recording of a phone conversation between Martel and his longtime friend, Jason Bobak.

"It was all my fault," Martel tells Bobak. "I was going to kill myself the night that happened because I just panicked. I tried to hide it."

Martel then describes to Bobak how he struggled with Rae: "We weren't fist-fighting, but it was darned close. It turned into a wrestling match.

"The knife was beside the bed. She picked up first and then it ended up inside her."

Martel's lawyer, Balfour Der, asked Bobak if he had ever witnessed Rae being "verbally aggressive" or "push [Martel's] buttons to get him riled up."

Bobak answered yes, adding, "it went both ways."