Landy: The truth behind the statement is that Sweden does have more immigrants per capita than any other EU country and immigrants in Sweeden (and elsewhere) are more likely to commit crimes and are therefore disproportionally represented in the justice system (this can be compared to how blacks are more represented in the justice system in the US though I don't know how the numbers stack up).
What is also true is that Swedish media does not report ethnicity of criminals by default. So if a gang rob a kiosk, the report will say: "kiosk robbed by gang" and not "kiosk robbed by afghan/somali/white gang". People can make of that what they want, this is not a policy that I have a fixed opinion about.
Where you should be careful is that Sweden has a super high rate of reported rapes. This is because Sweden has the most progressive laws in terms of reporting rapes... que a gazillion right-wing stories about how immigrants are raping everyone in Sweden. This type of stories typically don't hold up to fact-checking because they are comparing apples and oranges.