HALIFAX -- After three weeks of evidence, the Crown has closed its case against a Halifax law school graduate accused in the violent death of his girlfriend, Kristin Johnston.

Nicholas Butcher, charged with second-degree murder, was arrested after the body of the Montreal-born yoga instructor was found in her Halifax-area home on March 26, 2016.

The Crown called its final witness to the stand Wednesday -- an expert in digital forensics who analyzed a laptop found in Johnston's home with a username of Kristin Johnston and found that it had been accessed hours before her death.

Blair MacLellan, who is self-employed but worked as a civilian for the RCMP's tech crime unit at the time of the alleged murder, said Facebook messages were opened on the computer around 1:40 a.m. on March 26, 2016.

"We could see that those were actually clicked on and looked at," MacLellan said of the messages, adding that the Facebook account had "cached credentials," meaning it would have logged in automatically.

Friends have testified they were hanging out with Johnston at an apartment elsewhere during the time frame the laptop was accessed.

The 14-member Nova Scotia Supreme Court jury has heard Johnston and her friend Lisa Abramowicz were at the flat of another friend, Michael Belyea, when Butcher, 36, unexpectedly appeared in the doorway, much to their bewilderment.

Abramowicz testified that Johnston had only obtained Belyea's address hours earlier, and had no idea how Butcher knew she was there. She said the three surmised that Butcher had looked at Johnston's Facebook messages.

Belyea told the jury that Johnston ended her relationship with Butcher that night, after a conversation with him outside of Belyea's apartment.

But Butcher returned to Belyea's, and found them kissing. Belyea said he left the flat to let them talk and when he returned, Butcher and Johnston were gone.

Hours later, the 32-year-old woman was found dead.

The jury has heard Butcher called 911 that morning and told the dispatcher he had killed his girlfriend and tried to kill himself. Breathing heavily and wailing, he said he had cut off his hand and needed help.

"I'm bleeding to death," said Butcher during the 15-minute call.

Police officers have testified that a blood-caked Butcher emerged from Johnston's home shirtless and wearing pyjama pants, and was missing his right hand.

Johnston's body was found on a bloody bed, next to a steak knife. On the floor of the bedroom was a mitre saw and a severed hand.

Butcher's hand was surgically reattached.

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.

She also said Johnston has "defensive injuries" on her palms and fingers.

The jury has heard Johnston had confided in several friends in the weeks, days and hours before her death about her relationship with Butcher, telling them she was not happy and wanted to end it.

Her yoga business in Halifax had just closed, and she had plans to leave Halifax behind and "start a new life" in Tofino, B.C., where her sister lived, her best friend Jennifer Hazard testified.

She was described by friends as "happy," "beautiful," and "bubbly" the night before she died, as she shared drinks at a trendy Halifax bar before going to Belyea's.

Johnston, whose brother owned a Bikram yoga studio in her hometown of Montreal, came to Halifax in 2011 with dreams of opening her own studio.

She was quickly embraced by the local yoga community, becoming known as a kind and determined businesswoman with a magnetic personality.

The jury has heard Butcher is a graduate of Dalhousie University law school and was having trouble finding an articling job. He worked for Young Drivers before his arrest.

The Crown closed its case after calling 31 witnesses over 11 court days.

The defence is not required to call evidence because the burden of proof rests with the Crown.

The trial resumes Thursday.