Sandra Day O'Connor

“ Our task is to fashion an appropriate standard of reasonableness, one that gives due weight to the difficult position of subpoena recipients but does not impair the strong governmental interests in affording grand juries wide latitude, avoiding minitrials on peripheral matters, and preserving a necessary level of secrecy. We begin by reiterating that the law presumes, absent a strong showing to the contrary, that a grand jury acts within the legitimate scope of its authority. ”

“ The District Court could have concluded from these facts that there was a reasonable possibility that the business records of R. Enterprises and MFR would produce information relevant to the grand jury's investigation into the interstate transportation of obscene materials. Respondents' blanket denial of any connection to Virginia did not suffice to render the District Court's conclusion invalid. A grand jury need not accept on faith the self-serving assertions of those who may have committed criminal acts. Rather, it is entitled to determine for itself whether a crime has been committed. ”

“ In short, the Government cannot be required to justify the issuance of a grand jury subpoena by presenting evidence sufficient to establish probable cause because the very purpose of requesting the information is to ascertain whether probable cause exists. ”