HALIFAX -- Nicholas Butcher testified in his own defence at his murder trial Thursday, describing affectionate messages he exchanged with the Montreal-born yoga instructor he's accused of killing.

Butcher, charged with second-degree murder, was arrested after the body of Kristin Johnston was found on a blood-soaked bed inside her Halifax-area home on March 26, 2016.

That same morning, Butcher called 911. He told the dispatcher he had killed his girlfriend and tried to kill himself. Breathing heavily and wailing, he also said he had cut off his hand.

"Today, you're going to hear Nicholas Butcher's side of the story," defence lawyer Peter Planetta told the 14-member jury during his brief opening address in Nova Scotia Supreme Court.

Planetta then called his client to the stand. Butcher placed his right hand -- which was surgically reattached -- on a bible and swore to tell the truth.

A stocky man with closely cropped hair and beard, the 36-year-old spoke about the stress Johnston was feeling in February 2016, as her yoga studio in Halifax was failing. He said she was behind on paying her rent, and despite efforts to revamp the business, it closed that month.

"It was a huge stressor for her," said Butcher, adding that he often helped run the Bikram yoga studio. "It was the reason she moved to Halifax. It was her baby."

Days after the business was shuttered, Johnston travelled to Florida to visit family, he said. While there, Johnston contemplated heading to Costa Rica to visit her friend Jennifer Hazard.

Reading a message Johnston had sent him, Butcher said: "I'm looking up flights to Costa (Rica). I can't do this unless I know it will not stress you out at all."

"Babe, you do what you need to do. I'll be all right," he replied in a message.

"You're too good to me," she said.

"You deserve it … Babe, I'm always going to be this good to you," said Butcher, whose voice wavered only once during his testimony Thursday.

Butcher then described messages they exchanged during her trip to Costa Rica in early March 2016.

In the messages, Johnston spoke about her lingering stress related to her business, including a lawsuit and about being "excited to get home and make a plan" with Butcher.

"I just wanted to say I love you and I'm so grateful for you," Butcher said, reading Johnston's message.

The trial has heard that Butcher and Johnston were in a relationship and were living together. However, the jury has also been told that Johnston broke up with him hours before her death.

Earlier in the trial, Hazard testified that Johnston talked about ending her relationship with Butcher during the trip to Costa Rica. She said the 32-year-old woman wanted to leave her Halifax life behind, and was "ready for a new chapter" in Tofino, B.C., where her sister lived.

Butcher, wearing a navy suit, white collared shirt and a navy tie, told the jury he graduated from Dalhousie University's law school in 2015, and spent that summer looking for work.

He said he was having financial difficulty in late September, and took on five part-time jobs. He said he eventually moved in with Johnston, partially for "financial reasons."

Butcher will be back on the stand Friday.

Medical examiner Dr. Marnie Wood testified that Johnston's death was caused by sharp force injuries to her neck that led to a fatal amount of bleeding, and that the injuries were consistent with being caused by a single-edge blade.

Police have testified a steak knife was on the bed next to Johnston's body.

Dr. Jonathan Trites, a head and neck surgeon, testified that along with Butcher's amputated hand, he also had 13 sharp wounds on his neck.

The Crown closed its case Wednesday after calling 31 witnesses to testify.