It's already hard to understand the culture in a country. I see also the difficulty of handling administrative matters for my American wife, from taxes to mortg

It's already hard to understand the culture in a country. I see also the difficulty of handling administrative matters for my American wife, from taxes to mortgage contracts. Everything of course in a second language. Even people's gestures or their facial expressions are different. To have to navigate the juridicial system in another country is a huge disadvantage. You will make errors which a native will never make. You will not know about options that are very clear to long term citizens. Etc. Etc. All in all, whatever the crime, you would like to have everybody the same chance in your juridicial system. Foreigners will have a disadvantage however.