In the case of McCarthy v. Philadelphia Civil Service Commission, 1975, the U.S Supreme Court ruled in favor of a police officer who was dismissed from his job due to his homosexuality. The court held that this dismissal violated the Equal Protection Clause of the Fourteenth Amendment as it constituted discrimination based on sexual orientation. The plaintiff, James E. McCarthy had been an exemplary officer with no record of misconduct or poor performance during his employment period but was fired solely because he admitted to being homosexual during a polygraph test conducted by internal affairs investigators looking into unrelated allegations against him and other officers at his precinct station house. This ruling set a precedent for future cases involving discrimination based on sexual orientation within public service jobs.

In the dissenting opinion for McCarthy v. Philadelphia Civil Service Commission, Justice Brennan disagreed with the majority's ruling that a public employee could be dismissed without a hearing if they refused to waive their Fifth Amendment rights during an investigation into alleged misconduct. He argued that this decision violated due process and was contrary to previous Supreme Court rulings which held that public employees cannot be forced to choose between their constitutional rights and their jobs. Furthermore, he contended that there were other ways for employers to deal with uncooperative employees in such investigations without resorting to dismissal or punishment. For instance, adverse inferences could be drawn from an employee's silence or refusal to answer questions during an investigation - something courts do regularly when defendants refuse testimony on self-incrimination grounds.