Yeah, in a way they're really just saying out loud the quiet part: that their job is to arrest people who "don't look right", quite independently of being an illegal immigrant, legal immigrant or even a citizen.

Having the "app" as an intermediary in the decision process is just a "computer says" way to isolate themselves from the responsabilities of what is in fact their choice (as the app was still configured/trained per their instructions so it's nothing but a computer agent dirctly or indirectly executing their instructions)