In addition to examining annual changes and trends in the various performance measure data, these data can be considered in relation to the estimated size of the unauthorized workforce or the potential number of employers employing these workers. [...] In 1999, for example, the Immigration and Naturalization Service (INS) unveiled an interior enforcement strategy, which, as explained by an INS official at the time, gave priority in the area of worksite enforcement to two types of cases: (1) criminal employer cases, in which there was a pattern or practice of knowingly employing unauthorized workers, and (2) cases of employers who abused their wo [...] We expect that the increased use of the administrative fines process will result in meaningful penalties for those who engage in the employment of unauthorized workers.18 Despite the increases in recent years, however, the number of Final Orders for civil money penalties remains very low relative to the number of U. S. employers. [...] In 2008 congressional testimony, DHS Secretary Michael Chertoff highlighted the number of administrative and criminal arrests in worksite enforcement operations in FY2007 as evidence of the progress being made by ICE on the worksite enforcement front.20 Between FY2008 and FY2009, as indicated in Table 3, the number of administrative arrests decreased by more than 65% and the number of criminal arr [...] Congressional Research Service 7 Immigration-Related Worksite Enforcement: Performance Measures Criminal Prosecutions and Fines Table 4 provides data on criminal prosecutions related to worksite enforcement investigations for FY2005-FY2009.25 These data build on the criminal arrest data in Table 3. As shown in Table 4, the number of criminal indictments and the number of convictions rose steadily.