Detention centers are located in several states and in Texas, ICE just released hundreds of illegals as did Arizona. Detentions centers can only hold the immigrants for 60 days unless a court hears their case. Almost none of the illegals have their paperwork processed due to volume much less even appear in court.
For a map of ICE published detention centers, click here. Thousands upon thousands are immediately transferred out to contracted organizations mostly operating as religious organizations but that is actually a front operation.