In an opinion released yesterday, the 4th U.S. Circuit Court of Appeals  has ruled that, absent express direction or authorization by federal statute or federal officials, local law enforcement agencies do not have the authority to detain or arrest individuals solely based upon suspected civil violations of federal immigration laws.
Writing for a three-judge panel of the Court, in a case arising out of the arrest of a Salvadoran dishwasher seized while eating a sandwich outside her workplace in the fall of 2008, Judge James A. Wynn, Jr. wrote:
We conclude that the deputies seized Santos for purposes of the Fourth Amendment when Deputy Openshaw gestured for her to stay seated after dispatch informed him of the outstanding civil ICE deportation warrant. At that time, the deputies’ only basis for detaining Santos was the civil ICE warrant. Yet as the defendants concede, the deputies were not authorized to engage in immigration law enforcement under the Sheriff’s Office’s agreement with the Attorney General. They thus lacked authority to enforce civil immigration law and violated Santos’s rights under the Fourth Amendment when they seized her solely on the basis of the outstanding civil ICE warrant.