Wrong question. The right question is, "were any of them US citizens or legal residents?" And the answer is yes, some of them were. For some of them the use of past tense is particularly appropriate because they are no more.
That is not the right question because a) zero mistakes is not a reasonable standard for any country-scale operation and b) legal residency does not preclude there being a valid reason for deportation such as violating the terms of that residency permit.
