Police have charged a 33-year-old man with second-degree murder in the death of Kristin Johnston, a yoga instructor in Halifax who was found dead in her home two weeks ago.

Nicholas Butcher, of Halifax, was arrested on Monday at noon and is in police custody. He appeared briefly in Halifax provincial court on Tuesday afternoon and was arraigned.

He was represented in court by a legal aid lawyer who declined to comment. Butcher is due back in court on April 27.

Police said they believe Johnston and Butcher were in a relationship. At the time of her death, police said he was staying at her home. They are not releasing her cause of death.

"We feel we know what the motivation was, but it's not something that we're going to discuss through the media, it will come out through the court process," Supt. Jim Perrin​ said Tuesday at a press conference.

Kristin Johnston, 32, moved from Montreal to Halifax about five years ago. (Facebook)

Significant injuries

Butcher had been found with significant injuries at Johnston's Oceanview Drive home on March 26, the day her body was discovered. He was arrested but released from custody for medical treatment due to his injuries.

He spent the next two weeks in the QEII Health Sciences Centre. He was arrested again after he was discharged from hospital, police said.

"We made the decision to hold off on the swearing of an information to allow our investigators time to interview him upon his release from hospital," Perrin said.

Police said the nature of his injuries is private information and would not say how he was injured. During the court appearance, he appeared to have one arm bent under the hooded sweatshirt he was wearing.

Nicholas Butcher made a brief appearance at Halifax provincial court this afternoon. (CBC)

In the hours after Johnston's body was discovered, police also interviewed a second man who was at her home. They ruled him out as a suspect after interviewing him.

On Tuesday, Perrin said police would not release any information about the second man's identity.

Perrin would not say who called 911 from inside the home, but said it was someone officers interviewed.

Law school graduate

Police said Butcher did not have a criminal record. He graduated from Dalhousie University's Schulich School of Law last spring. The Nova Scotia Barristers' Society said they have no record of him obtaining an articling position in the province.

He previously did a master of arts in history at the University of New Brunswick and an undergraduate degree at McGill University in Montreal.

Friends say their relationship was not going well and she was looking forward to a life without him.

Johnston, 32, was originally from Montreal and moved to Halifax about five years ago.

Her family says she moved east after falling in love with the city and developing a close circle of friends in Nova Scotia. She owned and operated Bikram Yoga Halifax. It closed earlier this year.

Johnston's friends gathered to celebrate her life and the contributions she made to the community at a memorial on April 9.