In the case County of Los Angeles et al. v. Davis et al., 1978, the U.S Supreme Court ruled that a case could be declared moot if interim relief or events have eradicated the effects of the alleged violation and there is no reasonable expectation that said violation will recur. The lawsuit was brought by two African American women who claimed they were discriminated against in hiring practices by Los Angeles County's Fire Department due to their race and sex. However, before reaching trial, both women were hired as dispatchers - one even promoted to supervisor - thus eliminating any personal stake in obtaining injunctive relief for themselves from discriminatory hiring practices. Furthermore, changes had been made to recruitment procedures which resulted in increased minority representation within the department; hence it was unlikely such discrimination would occur again.

In the dissenting opinion for County of Los Angeles v. Davis, Justice Brennan argued that the case should not have been declared moot because there was still a live controversy. He pointed out that while the specific discriminatory practices had ended, their effects continued to harm minority firefighters who were denied promotions due to past discrimination. Therefore, he believed it was necessary for courts to provide remedies even after discriminatory practices had ceased in order to rectify these ongoing harms and prevent future violations. Furthermore, he disagreed with the majority's assertion that no reasonable expectation existed of repeated violation by county officials since they only stopped discriminating under court order and could potentially resume if oversight is removed.