This WashPost article is fairly informative, though one has to read past the first paragraphs with the WashPost's
this-is-what-refugees-do-when-they-are-rejected message. The perp is an Uzbek. Guess what religion is followed by some 96% of Uzbeks? That's right ... Amish! The Swedish government had rejected this character's application for asylum for ties to terror-sympathizers. He was supposed to be deported last year, but had been in hiding for some 9 months.
They may have a decent one, but the Swedish government needs to do a whole lotta 'splainin' to Sweden's citizens!