Agricultural employers wondering why U.S. Immigration and Customs Enforcement might show up at their business should instead be asking when. The rise of ICEWhile multiple agencies may play a role in immigration enforcement, ICE, created in 2003 through the merger of the U.S. Customs Service and Immigration and Naturalization Service, leads most worksite enforcement operations. I-9 auditsICE uses I-9 audits to pursue criminal prosecution of employers who knowingly hire unauthorized workers or greatly mishandle I-9 filings. The notices, which Coutu said are usually delivered in person, inform employers that ICE will audit their hiring records. ICE I-9 audits may also expand to include payroll records, lists of current and former employees, and retention policies.