A Texas prison unit is being readied to house illegal immigrants likely to be arrested in Governor Greg Abbott's renewed enforcement of the border. State officials have emptied the Dolph Briscoe Unit in Dilley, about an hour southwest of San Antonio. They started transferring prisoners this week to other prisons with available room. A Texas Department of Criminal Justice spokesman says the Briscoe unit will be used as a holding facility for illegals arrested for state or federal crimes as part of the governor's Operation Lone Star.