Police, toxicology expert testify about evidence at Nicholas Butcher's murder trial

The court has heard evidence that Butcher, 36, cut off his hand with a saw and told 911 operators he killed his 32-year-old girlfriend, Kristin Johnston, a Montreal-born yoga teacher. He has pleaded not guilty in the Halifax woman's death.

Warning: This story and live blog contain graphic details

Nicholas Butcher is charged with second-degree murder in the 2016 death of Kristin Johnston. (Andrew Vaughan/Canadian Press)

The Crown called police officers and a toxicology expert to testify Monday as the second-degree murder trial of Nicholas Butcher entered its third week in Nova Scotia Supreme Court in Halifax.

The court has heard evidence that Butcher, 36, cut off his hand with a saw and told 911 operators he killed his 32-year-old girlfriend, Kristin Johnston, a Montreal-born yoga teacher. He has pleaded not guilty in the Halifax woman's death.

Toxicology expert Christopher Keddy testified alcohol was the only drug found in Johnston's system at the time of her death. Keddy, who took over the case after the original toxicologist retired, said Johnston's blood-alcohol level was double the legal limit for driving when she died. 

He told the court that any person with that level of intoxication can have trouble making sound decisions and recognizing risks, but may not give outward signs of being drunk.

911 call from Butcher

Halifax Regional Police Det. Const. Randy Wood was the first to testify on Monday. He collected evidence at the Purcells Cove-area home where Johnston was killed on March 26, 2016. 

Wood took the jury through the extremely graphic pictures of the crime scene.

In a chilling 911 call the jury heard last week, Butcher gasps and sobs, asking for help.

"I need help. I'm dying. I'm bleeding to death. I cut off my hand. I killed her," he said on the recording played in court last week.

The jury has heard Johnston was found dead in the master bedroom of her home, lying on the bed with the sheets soaked in blood.

A Halifax Regional Police officer testified last week her head was covered with a pillow and a black-handled steak knife was next to her on the bed.

A mitre saw was found in the bedroom, the officer told the court, and Butcher's severed hand was beside the saw.

Evidence collected

The jury also heard from detectives who seized evidence from the crime scene, including Butcher's pyjama bottoms and underwear, a knife, and razor blades found on the bed in the master bedroom where Johnston's body was found.

Det. Const. James Wasson with the Halifax Regional Police's forensic identification unit said some of the blood-stained items tested positive for Johnston's blood. Wasson accompanied Johnston's body from her home to the medical examiner's office, where an autopsy was performed.

Det. Const Michael Barkhouse, also with the forensic identification unit, collected evidence from Johnston's autopsy. He took pictures of jewellery removed from Johnston for the autopsy, including a naval piercing and an eyebrow piercing.

Barkhouse pointed out 10 neck wounds on Johnston as well as injuries to her left hand including her thumb. He also showed photos of injuries to her right hand.

Kristin Johnston ran a yoga studio in Halifax. She was considering moving when she died, the court has heard. (Kristin Johnston Legacy/Facebook)

Michelle Scott-Mascioli, a forensic DNA expert who works with the RCMP crime lab in Ottawa, was the final witness for Monday.

Scott-Mascioli told the jury she tested blood found on a razor blade, knife, a pair of sweat pants, a bed sheet, a hand print on a bed sheet and a swab off the mitre saw and the floor and walls inside the house.

Scott-Mascioli said tests on the knife revealed two DNA profiles: one was Johnston and the other was referred to as male suspect one. She said she doesn't get the names of suspects for legal reasons.

The trial began two weeks ago and is before a judge and jury. The Crown expects to call about 40 witnesses in the case, which is scheduled to run for 20 days.

The CBC's Blair Rhodes blogged from court