The 17-year-old offender pleaded guilty to second degree murder and aggravated assault following a series of gang-related shootings.
The Crown applied to have the young person sentenced as an adult.
The court found that the Crown failed to rebut the presumption of diminished moral blameworthiness, noting the youth's cognitive limitations, mental health issues, substance abuse, and vulnerability to older criminal peers.
The court also found that a youth sentence would be sufficient to hold the offender accountable.
The young person was sentenced to the maximum youth sentence of seven years for second degree murder, comprising four years in secure custody and three years of community supervision.