In recent years, there has been steady erosion in the separation between the federal responsibility to enforcement immigration laws and the responsibility of states and local governments to keep communities safe. Some states and localities have passed laws requiring their local law enforcement agencies to investigate the legal status of people they encounter or arrest. Often, these laws are pushed through by politicians over the objection of police who consider protecting the community from criminals to be their chief concern. As police have become involved in the enforcement of immigration laws, there has been a steady erosion of community policing.
If immigrants feel that by cooperating with the police they put themselves or their family members in jeopardy, they are more likely to avoid the police, even if they have information that might be valuable to the police. State and local police understand this, which is why they have spoken out against efforts to make them enforce federal immigration laws.
Police will have a greater likelihood of learning about trouble if members of the community feel safe coming forward with important information. This can only be accomplished if enforcement of immigration laws and criminal laws are kept separate.