While Durham’s local governments have not adopted formal sanctuary policies, which state law prohibits, its officials have been outspoken for years in their embrace of immigrants, who make up 15 percent of the county’s population. Early news and social media reports suggested that the officers worked for ICE, which enforces immigration law in the country’s interior. Customs and Border Protection spokesman Rob Brisley told The Assembly in an email that federal officers tried to call the nearest Durham city police station (but not the county sheriff’s office) before making the arrests, and no one answered.