Federal Immigration and Customs Enforcement officials sent subpoenas and threatening letters to Cook County Sheriff Tom Dart demanding he turn over jail inmates for civil immigration enforcement interviews. The letters warned the sheriff could face witness tampering charges if he did not comply, though state law prohibits the sheriff's office from releasing individuals in custody to federal agents. Similar letters were sent to Hennepin County Sheriff Dawanna Witt in Minneapolis, with officials calling the tactic a "scare tactic" targeting sanctuary jurisdictions.