At the time of the murders, the state of Mississippi made little effort to prosecute the guilty parties. The Federal Bureau of Investigation (FBI), under pro-civil-rights President Lyndon B. Johnson and Attorney General Robert F. Kennedy, conducted a vigorous investigation. A federal prosecutor, John Doar, circumventing dismissals by federal judges, convened a grand jury in December 1964. In November 1965 Solicitor General Thurgood Marshall appeared before the Supreme Court to defend the federal government's authority in bringing charges. Eighteen men, including Killen, were arrested and charged with conspiracy to violate the victims' civil rights in "United States v. Price".