Under the Fair Housing Act, the Department of Justice may file a lawsuit when there is reason to believe that a person has engaged in a "pattern or practice" of discrimination or has engaged in discrimination against a group of persons that raises an issue of "general public importance." Often, the Department's lawsuits allege that a defendant has done both.
The courts have found a "pattern or practice" when the evidence establishes that the discriminatory actions were the defendant's regular practice, rather than an isolated instance. This does not mean that the Department has to prove that a defendant always discriminates or that a large number of people have been affected. A "pattern or practice" means that the defendant has a policy of discriminating, even if the policy is not always followed.
The courts have held that the Attorney General has discretion to decide what constitutes an issue of "general public importance," and the courts will not second-guess that decision. Thus, the Department can bring suit even when a discriminatory act has occurred only once, if it affects a group of persons and the Department believes that the discrimination raises an issue of general public importance.
There is a different standard for bringing individual claims of discrimination under the Fair Housing Act.
The Department of Justice may also bring suit under the Equal Credit Opportunity Act where a creditor has engaged in a "pattern or practice" of discrimination in credit transactions.
The Department of Justice may also bring suit under Title II of the Civil Rights Act of 1964, where a public accommodation has engaged in "pattern or practice" of discrimination, denying individuals access to, or the same, rights, privileges, and opportunities that others have to enjoy a place of public accommodation.