The man stabbed the 18-year-old in the chest as he played football with friends on a pitch in Hässelby, a suburb of the capital. The group managed to escape to a nearby shop, but were followed by the attacker, who continued to make threats against them. The teenager later died of his injuries.
The killer told police he targeted his victim after recognizing him from a previous fight, but the Stockholm District Court said it had not found evidence to back up that claim.
Tests showed that the murderer did not suffer from a serious psychiatric disorder, and was therefore responsible for his actions.
The man’s lawyer, Sargon De Basso, said he would decide next week whether to appeal. He said the crime should have been categorized as manslaughter:
“We think it is wrong of the court to find that this was a murder,” he said.