Require all people crossing the border to give an information sheet WITH fingerprints or biometric data so we know who is crossing into our country.  This should be checked on each entry and exit.  If someone has been deported and re-enters illegally they would be caught at the border, not at a crime scene later.  Then they can be incarcerated for re-entry.  If people don't want to give this data then they are probably here for illegal purposes.

To identify all people who will cross in the future.