Poland already has plenty of murders unfortunately. Also domestic violence
You mean like that Polish migrant who went to the UK, got sick of his girlfriend and so tried to bury her alive?
And that Polish migrant who went to the UK, got sick of her boyfriend and so stamped on his head until he was dead? From memory that woman won a court case which prevents her from being deported from the UK after she finishes her sentence.
Or perhaps you mean that Polish who went to the UK, got sick of not having girlfriend and so raped and tried to murder a woman and kept claiming it was nothing to do with him even though her DNA had been found inside the victim?
Or maybe you mean the convicted Polish rapist who went to the UK and raped two more women there?
Or perhaps you mean the convicted Polish rapist who went to the UK and knocked out a disabled man before dragging him into the road and leaving him in the path of a double-decker bus?
I think it's best if we all agree that some people from every nationality will be utterly vile people and that those few people should not be used as an excuse to keep all of those people from going to whatever country.