It used to be a fairly lengthy process. Because of the new immigration laws put in place by Homeland Security/Congress the deportation process is in most cases quite rapid. Usually the local authorities take the person into custody and hold them for the INS, who transfer them to a federal detainment facility. Not a prison/jail unless the person has committed a crime other than illegal entry. Border guards now have "deportation authority" as do some other federal entities. Regulations are very strict, now and many civil rights organizations are protesting the lack of "due process" for illegal immigrants. Meaning the court hearing, appeals, etc are often waived or speeded up, depending on the situation.