Check this out:
True, the Bureau of Immigration and Customs Enforcement has primary responsibility for investigating and enforcing immigration laws, but that doesn't mean local police should turn away from lawbreakers they encounter.
There are many legitimate reasons why knowing immigration status is important on a day-to-day basis. For example, when making a determination whether to release a person pending issuance of a summons or to hold them for bail because they don't have ties to the community. And that's just one ROUTINE example.
As we've said many times, Milwaukee burns while the politically-correct (or those who want to be) fiddle.