A US citizen can have an ICE hold placed on them when ICE does not know or believe them to be a citizen. Consult with and hire a lawyer.
Samuel Ouya Maina, Esq. 415.391.6612 email@example.com Law Offices of S. Ouya Maina, PC 332 Pine Street, Suite 707 San Francisco, CA 94104
No. Provide proof of citizenship. He may have to do this at Removal Hearing if it gets that far. Do retain an experienced Immigration Attorney for assistance.
Law Offices of J Thomas Smith J.D., Ph.D 11500 Northwest Freeway, Suite 280 Houston, TX 77092 713-LAWYER-2 www.MyImmigrationLawyer.info NOTE: Responses are for the education of the community at large and is not intended to be "legal advice." No attorney-client relationship is established by responses or comments.
One of two things might be happening. It is possible that ICE doesn't know that he is a US citizen. Another possibility is that an illegal act was committed prior to him becoming a US citizen, assuming the inmate gained his citizenship through naturalization.
Contact an attorney and have the attorney communicate with ICE and the detaining agency.