Catherine Campbell murder trial hears from DNA expert

Off-duty police officer Catherine Campbell's blood was found on a stereo, television, cabinet and the floor of the Halifax apartment where police say she was murdered, a DNA expert with the RCMP testified Tuesday.

Dr. Gregory Litzenberger told a Nova Scotia Supreme Court jury that he tested various blood swabs taken by police at the apartment on McCully Street and established several matched Campbell's DNA.

Christopher Garnier, 30, is on trial in a Halifax courtroom for second-degree murder in Campbell's death and for interfering with human remains. He has pleaded not guilty to both counts.

Litzenberger told the jury he also tested a T-shirt found in a dumpster across the street from the McCully Street apartment. He said two blood stains matched Campbell's DNA.

Tests on some fingernail clippings taken from Campbell during the autopsy on her body revealed Campbell's blood. Other clippings showed Campbell and Garnier's DNA, Litzenberger said. He testified the DNA was most likely transferred by friction, such as scratching.

Litzenberger noted he did not find any semen on Campbell's body or underwear. Garnier has told police in a videotaped statement that he doesn't believe they had sex after they met at a Halifax bar and returned to the apartment.

The Crown alleges Garnier murdered Campbell in the early-morning hours of Sept. 11, 2015, put her body in a green compost bin and dumped her under the Macdonald Bridge, where the 36-year-old was discovered several days later.

The defence last week presented a hypothetical scenario suggesting Campbell died during a consensual sexual encounter, after encouraging Garnier to choke her.

The jury also heard Tuesday from a blood-splatter expert, RCMP Sgt. Adrian Butler, who testified he examined the McCully Street apartment. He said some sort of force caused blood to fly through the air and land on the speaker, but he could not say how much force was applied.

Butler agreed with Garnier's defence lawyer, Joel Pink, that not a lot of blood was found in the apartment. He also agreed there was evidence the scene had been cleaned up.

Six spatter stains were found on the floor of the apartment hallway, Butler said, and at least 26 small spatter stains in one section of the floor.

Spatter stains found on the wall appeared to have been caused by blood droplets travelling downward and hitting the wall, Butler testified. He noted other stains, including on the wheel of an automatic vacuum that appeared to have rolled through blood.

The blood on the television was a contact stain, Butler said, but he could not say for certain how it got there.

The jury also heard from Blair MacLellan, a digital forensics and data recovery expert, who said he analyzed a computer seized during the police investigation.

MacLellan said he checked the computer's browser history to see if anyone had searched for Catherine Campbell, but found nothing. He noted someone had searched for information on the side-effects of Cipralex, an anti-depressant Garnier admitted to taking.

The queries were for Cipralex and alcohol, Cipralex and violence, and Cipralex and memory loss on Sept. 15, 2015 — about four days after Campbell's alleged murder.

On Tuesday, the jury continued watching a 9½-hour video of Garnier's police interrogation following his arrest on Sept. 16, 2015. RCMP Cpl. Jody Allison interviewed Garnier at the RCMP detachment in Lower Sackville.

During a portion of the video watched Tuesday, Allison showed Garnier more of the security video from the Soma Clinic on Agricola Street that showed a barefoot man pulling a green bin.

Allison asked Garnier if his feet weren't sore from walking barefoot through city streets. Police took photos of the soles of Garnier's feet after he was arrested. There didn't appear to be any marks.

"There's no doubt she was killed in the apartment, Chris. I saw blood right at the scene. Right in front of the pullout couch. That's where she died, wasn't it?" asked Allison.

Garnier doesn't say much throughout the portion of the video played in court Tuesday, but he repeats that he had been told not to speak. There are roughly six more hours of interrogation to watch.

The trial resumes Wednesday.

The case is scheduled to run until Dec. 21, with a verdict expected just before Christmas.

The CBC's Blair Rhodes live blogged from court.