A jury has found a 22-year-old woman not guilty of second-degree murder in the stabbing death of a 68-year-old Winnipeg rooming-house resident.

Jurors reached their verdict early Tuesday afternoon after just two hours of deliberations. 

Jurors heard Brian O'Donnell was on his way to his morning coffee at a nearby McDonald's restaurant on June 30, 2013 when an attacker chased him back to his rooming house in the 300 block of Langside Street and stabbed him several times outside his room.

Witnesses testified the woman turned up at a Furby Street apartment later that morning with a knife and blood on her shirt, saying she had "stabbed someone."

Police later recovered a large "commando-style" knife hidden in a couch where the woman had been sitting. An analysis of the knife found O'Donnell's DNA on the blade. 

'We will never know exactly why' man was killed

Jurors didn't need to establish a motive to find the woman guilty of the killing, Crown attorney Paul Cooper said in a closing argument Monday.

"We know what killed him, but we will never know exactly why Brian O'Donnell was killed," Cooper said. "The Crown doesn't need to prove a motive … It doesn't make [her] any less guilty of murder for its absence."

By their verdict, jurors appeared to support the defence's assertion there was no direct evidence tying the woman to the killing.

"There is no evidence to say she was even at 375 Langside — not a fingerprint, not a swab, no DNA, not a hair, not a fibre, and certainly not a witness," defence lawyer Amanda Sansregret told jurors.

Sansregret conceded "it was a very reasonable inference" to conclude the seized knife was used to kill O'Donnell. But an analysis of the knife handle yielded genetic material from at least three people, none of whom could be positively identified, Sansregret said.