It was in November last year that the girl, 15 at the time, entered an apartment building in Helsingborg, poured gasoline on the social worker's door and set it on fire.
According to the prosecutor, it was revenge for a decision the person had previously made that affected a relative of one of those involved.
The girl, who is now 16, has been convicted of arson by the Helsingborg District Court, but acquitted of attempted murder. She has been sentenced to juvenile detention.
The 19-year-old who allegedly caused the girl to set fire to the door is being convicted of, among other things, instigation of attempted murder. According to P4, three other teenagers will be convicted of involvement.
