Since before, three men aged 19, 31 and 32, who have been charged with, among other things, aiding and abetting murder, have been in custody.
They were released on bail during the last day of the trial and were acquitted today by the district court.
The 17-year-old was sentenced to closed youth care for two years and 11 months.
If he had been an adult, he would have been sentenced to 18 years.
The district court writes that when they compile all the evidence such as DNA, descriptions and comparison with surveillance cameras, it is beyond reasonable doubt that the teenager, who was 16 at the time, is the perpetrator.
The now-convicted 17-year-old has been sitting in a locked youth home at the State Board of Institutions, Sis, for some time now.
It was in March last year that a man dressed in black with a mask and a gun in his hand ran into a gym in Vasastan in central Stockholm.
He fired three shots and one of the shots hit a 55-year-old man in the head, who later died of his injuries.
The text is updated