This is an excellent unpublished BIA decision on suppression of evidence in Immigration Court.
Suppressing evidence of alienage that was gathered as the result of an unlawful stop or search is incredibly difficult, and the circuit courts are all over the place on what is required.
This decision makes clear that racial profiling in a traffic stop may be sufficient to require suppression of evidence obtained subject to that arrest. The BIA held that even where the agency that conduct the unlawful search was the local police, not ICE, the evidence they gathered as a result of the search could be suppressed.
What this decision doesn’t address is where the stop was “egregious” under the Fourth Amendment.” That’s where many of the appellate courts have ruled against suppression (Eighth Circuit I’m looking at you).