A Timmins man convicted of first-degree murder and sentenced to life in prison has won an appeal to have the verdict overturned.

Byron Spence can now be retried for the 2009 shooting death of his half-brother, Jonah Trapper.

It took the jury nearly 24 hours to decide Spence's fate in September of 2014.

Overwhelming evidence resulted in a conviction on a first degree murder charge and a life sentence for the then 30-year-old.

However, the conviction and the sentence were appealed on several grounds.

"The outcome, I think is very unfortunate," said Gregory Leslie, Spence's attorney.

"There are certain things that a lot of people are not aware of, including the jury."

In the 27-page appeal judgement released this week, the Ontario Court of Appeal lists errors made by presiding Justice Robert Riopelle.

It said he was in error when instructing the jury and allowing only parts of Spence's post- shooting interview with police into evidence.

"Although the evidence of the appellant's (Spence) mental health struggles was rather thin, in combination with his claim of accident, it was capable of raising reasonable doubt on the issue of intent," reads a portion of the appeal.

Intent is required for a first degree murder conviction.

The Court of Appeal objected to the below quote from Justice Riopelle; as he ruled out mental illness as a plausible defence.

"I am referring here to the whiff of mental illness or those other issues. There is a presumption at law that a person intends what he does voluntarily and where there is guilt, it can be displaced by intoxication. It could be displaced as well by proof of mental issues."

The appeal court said Riopelle went on to tell the jury that he didn’t think mental illness was an issue.

The successful appeal will see Spence get a new trial. 

It doesn’t dispute Spence's role in the death of his half-brother, but seeks to re-examine whether it was first-degree murder.

No court dates have been set, but the retrial will take place in Timmins.