HALIFAX -- Nicholas Butcher insisted Monday that the Montreal-born yoga instructor he's accused of killing actually tried to kill him, as the defence closed its case at the second-degree murder trial.

Butcher, the lone defence witness, told the 14-member jury the pair had been sleeping at Kristin Johnston's home on March 26, 2016, when he awoke to someone stabbing him in the throat with a knife.

The 36-year-old law school graduate testified that it was dark and he couldn't see who it was, but managed to grab the knife and fight back -- realizing seconds later he'd killed Johnston.

During her cross-examination, Crown lawyer Carla Ball noted wounds on Butcher's neck were located symmetrically on the right and left sides and in the centre -- a pattern she suggested would be hard to achieve if someone had attacked him in the dark.

She suggested Butcher's neck wounds were self-inflicted.

"The next thing she knows is that a knife is being plunged repeatedly into her neck by you until you are satisfied that she is dead," Ball said, raising her voice.

"And then you thought, 'What am I going to do? I have to kill myself' ... and you took that knife and thought, 'I watched her die by the knife being plunged into her neck so I'm going to use that knife and do the same thing to myself. That's what you did, didn't you?"

Butcher denied Ball's suggestions.

"She tried to murder me," Butcher said calmly in a deep voice.

Dr. Jonathan Trites, a head and neck surgeon, had testified that Butcher had 13 sharp wounds on his neck.

Ball also pointed out that Johnston had 10 wounds on her neck, but Butcher testified he stabbed her about four times. He did not offer an explanation for the discrepancy.

She noted Butcher told a police officer "sorry" after they arrived on the scene, and told a doctor at the hospital he had "messed up."

"That's because you took that knife quite intentionally and plunged it 10 times into Kristin's neck," said Ball.

Butcher replied, "No. It was not intentional."

Breaking down on the stand last week, Butcher told the jury he tried to kill himself after realizing he had killed Johnston. He said he slit his wrist with the knife, a razor blade, and then cut off his right hand with a mitre saw. His hand was surgically reattached.

Medical examiner Dr. Marnie Wood testified that Johnston had "defensive injuries" on her hands and fingers.

Butcher was in a relationship with the 32-year-old yoga teacher, but friends of Johnston's testified in Nova Scotia Supreme Court she had broken up with him hours before her death.

Butcher, a graduate of Dalhousie University law school who was having difficulty finding an articling job, acknowledged Monday that he was $200,000 in debt from school.

The jury heard messages in which Butcher told his landlord how "stressed" he was over his inability to pay rent on time.

The jury heard from 32 witnesses over 14 court days. Lawyers will make closing submissions on Thursday.

Butcher has pleaded not guilty.