He needs to hire a fine Kentucky attorney who will put his case back on calendar and explain to the judge that your bf couldn't make his court date because he was being detained by ICE. I am sure the judge will pull the warrant; your bf will still have to defend whatever the underlying charges are.
Hire a criminal defense attorney in your area to locate the state case and redocket it to set aside/recall the bench warrant ASAP. www.kacdl.net
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..