The body was found in a garage in the neighbourhood of Skärholmen in west Stockholm in January.
The 19-year-old was found guilty of murder, aggravated arson and disturbing the peace of the dead (brott mot griftefrid) by Södertörn district court.
The seriousness of the crime is such that the 19-year-old would have been sentenced to life in prison had he been older, the court said in its judgement. He had not yet turned 19 when he committed the crime. Police found a pair of shoes and a pair of gloves with blood traces from the victim at the 19-year-old’s residence.
The 36-year-old was shot twice in a cellar connected to the property and was then placed in the back seat of a car the 19-year-old ignited with petrol. The court stated that the 19-year-old must have had help to move the body, but it has not proved possible to discover who else might have been involved.
A 21-year-old man, who was charged as an accessory to arson, is thought to have purchased a container of petrol and given it to the 19-year-old. The court did not, however, find beyond a reasonable doubt that the 21-year-old knew what the petrol was to be used for and he was subsequently acquitted.