Stastistics about suspects are most commonly used in studies like these because the police, due to the seperation of powers, usually has no or at least less statistics of the actual results of charges.
That low resolution rate alone introduces a margin of error that is larger than the difference between immigrant and non-immigrant suspects. It is therefore possible that the much higher immigrant suspect rate is entirely a result of biases.
I’m not suggesting however that because they are immigrants they commit more crime. Note most violence is committed by 2nd generation immigrants - so they’ve been born here. How’s that for a failure of society...
They are simply people on the outside living surrounded by people leading lives they cannot relate to.
We’ve made it terribly difficult to attain this norm life as well making it even more unrelatable.