A Nebraska civil rights group is suing Sarpy County on behalf of a man who says he was jailed for four days because sheriff’s deputies wrongly believed he was an illegal immigrant.

The Nebraska chapter of the American Civil Liberties Union says 48-year-old Ramon Mendoza, of Papillion, was jailed in March 2010. In a lawsuit filed Thursday in Sarpy County District Court, Mendoza says he was pulled over and arrested by a sheriff’s deputy for not having a valid driver’s license or proof of car insurance.

The lawsuit says Mendoza was not allowed to call his family or a lawyer and that law enforcement officials used racial slurs to address him. It also says officials ignore a naturalization certificate, Social Security card and other documents provided by his family.