Missouri Senator Claire McCaskill is leading the push to mandate use of a system that verifies workers’ statuses after the recent slaying of a University of Iowa student by an illegal immigrant. McCaskill has introduced the E-Verify System Act of 2018. The bill would require that all employers use the system to ensure that new hires are United States citizens or foreign nationals that are authorized to work here. During the investigation into the death of Molly Tibbetts, it was learned that her accused killer had been in the country illegally for years. His employers never used the E-Verify system to make sure that it was legal for them to employ him.