A former Windsor resident has been found not guilty in a sexual assault case that dates back to 1990.

John Wuschenny, 57, was found not guilty of five charges, including sexual assault and forcible confinement.

The charges stem from an alleged break and enter and assault on a woman in September, 1990.

Wuschenny was a suspect then, but not charged till 2016.

Court heard the decision came down to DNA evidence.  Wuschenny's semen was found on a T-shirt seized by police, but not tested until 2015.

Justice Renee Pomerance ruled "the link between the T-shirt and the crimes is rooted in assumptions rather than evidence."

Wuschenny admits it's his DNA on the T-shirt seized by Windsor police. Scientists testified there is a 1 in 5.7 trillion chance it's someone else.

He never explained why his semen would be on the shirt but Pomerance ruled he doesn't need to. The onus of proof, beyond a reasonable doubt, is on Crown Attorney Walter Costa.

"The Crown has failed to link the T-shirt to the crime," she said.

The other key piece of evidence for the Crown was a photo lineup, done by police in February, 1991. Court heard Wuschenny refused to participate in a live lineup.

Police assembled 12 photographs, based on the victim's description of her attacker.

She identified Wuschenny by telling police: "I get the same feeling that I've seen him before in my room...thinking he was good looking, so is number 5, so yeah, number 5."

But Pomerance rejected the entire lineup evidence because "the accused's photograph leaps off the page, as if it is highlighted. It draws the eye. It has a different coloured background."

The complainant, whose identity is protected by a court-ordered publication ban, left the Courtroom before the end of the verdict.

But Justice Pomerance spoke of her, in her decision. "I have no doubt that the crimes occurred as she described them."

She went on to say, "I expect that she might have been hoping for some degree of closure. I cannot provide that to her in the form of finding guilt. What I can do, and indeed, must do, is ensure that the tragedy of the crime is not compounded by the further tragedy of an unsafe conviction."

Crown Attorney Walter Costa declined to comment after the verdict.

Defence lawyer Andrew Telford-Keogh said Mr. Wuschenny is relieved and "processing" this decision.

After 33 months in jail, and being a "person of interest" by police in 1990 and again when the investigation reopened in 2015, Telford-Keogh says his client is looking forward to getting on with his life.