Vice President May Be Indicted For Illegal Activity
Raw interviewed Marcy Wheeler of FDL who is covering the Libby Trial. She questioned whether the Vice President could be indicted.
The answer is: Yes, case law and legal scholars fall down on the side of, "It is possible for a prosecutor, outside Congress, to indict a Vice President or President." Grand Juries, state attorney generals, and other prosecutors may also legally, outside Congress, indict the Vice President.
Ref: Details how a sitting President or Vice President can be indicted outside the impeachment process.
Ref Fitz appears to beleive Cheney attempted to shape recollectios with Libby.
"And I’m still not convinced that you can indict a sitting vice president for something he did as a sitting vice president. Agnew was indicted for something he did before." Ref
The answer is: Yes, a Vice President can be indicted for something he did while Vice President.
Here's the case law supporting indicting a sitting Vice President or President while in office: Visit here for details