It was written by the same person as this story and is time stamped about a month before the Economist piece (they anon). But the articles don't particularly seem to be independent phenomena.
The LocalSE (linked above you can search for more by yourself I've had people mention to me that it apparently is a neonazi site but i'm pretty sure were to the left of Corbyn so make up your own mind) and Radio Sweden (which is Sweden's official broadcaster) all have the same stories.
(these are the 3 first results retrieved by searching "radio sweden shootings" (without quotes) on Google.co.uk in incognito mode. YRMV)
Sveriges Radio is essentially Swedish NPR or the BBC (pre television) so I have very high doubts that is pushes some highly contentious political agenda....
I'm aware it isn't uncommon, it's just less remarkable that a couple outfits would carry opinion pieces by the same person than it might be if they were opinion pieces by different people.
And that's the part of the article people are responding to, the opinion, the stuff that isn't in the Sveriges text, about how Sweden should be afraid of what it has done to itself. The Sveriges piece does mention that the homicide rate is still lower than Finland...
And while I don't think that Sweden is as dangerous as Mexico or even the US I do think there is a growing problem there and what scares me even more is the response you often get which what the GP posted above is the most "vanilla" version of it, he or she simply dismissed it and asked if HN is becoming Fox News more often than not you'll simply be stamped as a "trump supporter/nazi/alt-righter" regardless of the context by simply trying to discuss the issue.
The problem is that you can pull articles from early 2017 that show the same thing just talking about 2016, while every year seems to be an election year in some places it doesn't really seem to be a made up story.
I don't really understand the "counter arguments" presented here are the statistics wrong? because these seems to be official statistics reported by all Swedish media and produced by the Swedish government.