Calgary police announced Wednesday that a fourth youth has been arrested and charged with first-degree murder in the death of 16-year-old Carter Spivak-Villeneuve.

Police already arrested and charged three other 15-year-0ld boys with first-degree murder earlier this month.

On Tuesday, a fourth youth was arrested and charged.

None of them can be named under the provisions of the Youth Criminal Justice Act.

On Aug. 1, officers were called out to a home in the 300 block of Abergale Drive Northeast for reports of a person in medical distress.

That person was later identified as Spivak-Villeneuve, who died from his injuries.

Police said an autopsy confirmed his death was a homicide and they believe the victim and the accused teens knew each other.

Police also said the seriousness of the charges reflects their belief that the death was the result of a planned attack during a “stupid dispute” over “regular teenage stuff.”