A man charged in connection with the disappearance of a Dartmouth woman now believed dead was charged with assaulting her before, according to police and court documents.

Halifax Regional Police arrested 41-year-old Owen Patrick Nelson Tuesday afternoon in the Highfield Park Drive area of Dartmouth.

Nelson has been charged with interfering with human remains, assault, and two counts of breach of probation in connection with the disappearance of 40-year-old Karen Lee MacKenzie.

“There are six counts before the court right now, and (Nelson) hasn't entered a plea at this stage,” said defence lawyer Michelle James.

MacKenzie was last seen at 95 Highfield Park Drive on Feb. 25. She was reported missing to police on March 3.

Investigators initially said they were treating her disappearance as suspicious. Now they say they believe she is dead, although her body has yet to be found.

“Every time we get a lead or a tip or information or evidence or speak to an additional witness, any information they provide us, the investigators go forward. If that leads them to believe that searching a certain place is the next step, then that's where they'll go,” says Const. Carol McIssac of Halifax Regional Police.

Court documents show Nelson was charged twice last year for offences against Karen MacKenzie involving choking and assault. He was also ordered to stay away from her. A previous order meant he was to abstain from drugs and alcohol.

Nelson made a brief appearance Thursday in Dartmouth provincial court.

When he was led away, Gary Spears was there to see it. He says he's a friend of the accused, but hadn't seen him in a while.

“He was trying to, I don’t know, get his life back together. That's all I knew,” says Spears. “He just cut off anyone that was drinking and he was trying to get away from drinking.”

Kevin Dupuis, a long-time friend of MacKenzie, tells CTV News he’s been devastated since she went missing.

“Karen wouldn’t stop caring,” Dupuis said. “One thing that she taught me to do was surprise people with gifts. She loved her family and she spoke more about her family than they would know.”

Nelson has been remanded into custody until his next court appearance on March 26.

Police are asking for anyone with information to come forward.

With files from CTV Atlantic’s Heidi Petracek.