II) Prosecution of Vice President and Other Federal Officials
While there are different legal opinions about the President, there is a general consensus that Vice President and other “civil officers” of the United States can be indicted and prosecuted while they are still in office, prior to any impeachment. There are numerous legal cases that have firmly established this rule. For instance, in 1804, Aaron Burr, while Vice President, was indicted for the killing of Alexander Hamilton both in the state of New York and New Jersey. Burr never claimed any immunity from prosecution in the case, and had to serve out his office with the stigma of indictment.
Likewise, Spiro T. Agnew, while Vice President, was investigated by the U.S. Attorney in Baltimore for allegedly receiving payoffs from contractors when Mr. Agnew was governor of Maryland. Before entering a plea bargain to a reduced charge and resignation, Vice President Agnew made a motion to the federal court to enjoin the grand jury proceedings against him on the ground of immunity while in office. In response, then-Solicitor General Robert Bork filed a brief arguing that “considerations based upon the Constitution’s text, history, and rationale which indicate that all civil officers of the United States other than the President are amenable to the federal criminal process either before or after the conclusion of impeachment proceedings.
http://news.lawreader.com/?p=171