Barr v. City of Columbia, 378 U.S. 146 (1964), is a United States Supreme Court case in which the Court reversed the convictions of five African Americans who were refused service at a lunch counter of a department store based upon a prior Court decision, holding that there was insufficient evidence to support a breach of peace conviction and that criminal trespass convictions would be reversed for the reasons stated in another case that was decided that same day, Bouie v. City of Columbia, 378 U.S. 347 (1964). Bouie held that the retroactive application of expanded construction of a criminal statute was barred by due process of ex post facto laws.