If he is an alien, unauthorized to stay in the country, it is ICE's responsibility to remove him. Country jail informs ICE. ICE places detainer against his name and he cannot be released unless they fail to pick him up with 48 hours not counting weekends ad holidays.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.
Whether he gets deported depends on a number of factors including what his immigration status is, and what crimes he was convicted of.
Mr. Shusterman is a former INS Trial Attorney (1976-82) with over 35 years of immigration experience. His response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Shusterman's statement above does not create an attorney/client relationship.
They can deport him immediately if he has been in the country for less than 2 years or if he signs a document agreeing to be deported without seeing a judge. Otherwise, he will have the opportunity to go before a judge. If this is his first OVI AND his blood alcohol level was not extremely high AND he has other evidence that he is (generally) a responsible person, he can ask the judge to release him on bond. He should try to have documentary evidence that he has strong ties to the community and is no danger to the community. Whether or not he gets out on bond, he can apply for "relief" from deportation if he qualifies. You should speak to a lawyer immediately.
You should always consult with an experienced immigration attorney to make certain that the advice you received is appropriate for your particular immigration case.
He will be given a charging document called a Notice to Appear (NTA) and he may have a bond set or he may be held without a bond. He will eventually be scheduled for a removal hearing. At the removal hearing he will have an opportunity to reply to the NTA and present reasons for not being removed from the US. He also has the option of requesting removal. he should have legal representation before the Cleveland immigration court. The earlier in the process the better.
It is possible that he will not be deported. It depends on numerous factors, as noted by the other attorneys, including: his immigration status, if he has other convictions, and whether he is eligible for any type of immigration benefits or relief that will allow him to remain in the United States even if he found deportable. I suggest you speak to an immigration attorney who will help you through this process.