The murder trial for a man accused in the stabbing death of a 19-year-old woman six years ago in Dartmouth, N.S., has been stayed after a key witness "significantly" changed his story, the Crown said Monday.

The accused, Damarqus Shane Beals, had pleaded not guilty to second-degree murder in the Jan. 8, 2011 death of Keya Simon. He left Nova Scotia Supreme Court in Halifax on Monday morning with all bail conditions lifted.

Crown attorney Scott Morrison said a key witness offered information to police and during the preliminary hearing that was different than information given during a meeting with prosecutors last week.

"In the course of that meeting, that witness disclosed an account that was significantly different from what he had told police throughout the investigation and also during the preliminary inquiry," Morrison said Monday outside court.

"As a result of that, we determined there was no realistic prospect for conviction."

1 year to decide fate of prosecution

Simon was killed while attending a party at her sister's apartment on Pinecrest Drive in Dartmouth.

Her mother, Torina Simon, told reporters last week she planned to attend the entire trial despite how painful it would be to relive the events.

"(Keya's) not here so I have to stand for her," she said outside the courtroom last Tuesday as the trial got underway.

"It's hard but I have to close that chapter."

The Crown has one year to decide whether it wants to resume the prosecution.

2nd witness hit by car

The Crown added the stay of proceedings is unrelated to another key witness who suffered life-threatening injuries last week when she was hit by a vehicle.

"Certainly there is a witness who was injured," Morrison said outside court. "It was an entirely unrelated event and not in any way connected to this prosecution."​

Last Thursday, Terrie-Lynn Atwood, 25, was sent to hospital with life-threatening injuries after she was hit by a car on Farrell Street in Dartmouth.

A 52-year-old man has been charged with attempted murder in the incident. At the time of the arrest, police said they found crack cocaine, cash and drug paraphernalia.

Police said the accused and Atwood are known to each other and had been arguing.