Federal officials are threatening criminal charges against two county sheriffs who they say declined to give immigration agents access to inmates subject to deportation, according to the New York Times. Hennepin County Sheriff Dawanna Witt and Cook County, Illinois, Sheriff Tom Dart reportedly received letters hand-delivered by federal agents in early July. The New York Times said the letters asserted that failing to hand over inmates sought by ICE could lead to the county sheriffs being charged federally with witness tampering. Legal experts say the threatened witness tampering charges would likely be difficult to prosecute, the New York Times reported. Sheriff Witt posted the following response on social media:“In the past few weeks, federal officials have served warnings threatening to arrest me personally for what they describe as witness tampering.