In a unanimous decision Lewis v. Chicago, the Supreme Court (Scalia) decided "[a] plaintiff who does not file a timely charge challenging the adoption of a practice may assert a disparate-impact claim in a timely charge challenging the employer’s later application of that practice as long as he alleges each of the elements of a disparate-impact claim." Chicago used test results to select firefighters for training classes. Allegedly it had a disparate impact on persons protected by Title VII. Disparate impact claims do not require proof of intentional discrimination. A disparate impact claim “is established” if an employer “uses” an “employment practice” that “causes a disparate impact” on one of the criteria prohibited by Title VII.  42 U.S.C. §2000e–2(k)(1)(A)(i). Although the original test was scored outside of the filing period of the Charge of Discrimination giving rise to this suit, the "use" of the results of the test to exclude those making under a certain score arguably created a disparate impact each time the city filled a new class of firefighters.