Scooter Libby -- Lies, Reasons, and Commutations!

In this installment of What The Media Doesn't Tell You, Dean Lawrence R. Velvel of MSL discusses Scooter Libby; Trial, Conviction, and commutation with Professors Constance Rudnick and Andrej Starkis, both of MSL. During opening statements, Libby's attorney stated that Vice President Cheney would testify, yet he never did. What did Libby know about Valerie Plame that caused him to lie to the grand jury? Did Libby lie to the grand jury to keep the heat off Cheney? In addition, why did Libby receive a commutation?