Bill Richardson withdraw from Commerce Secretary of Obama ´s cabinet

Bill Richardson the governor of New Mexico had to withdraw from consideration of being commerce secretary in the future Obama cabinet because he is under grand jury investigation in Albuquerque. Richardson is being investigated for his dealings with the financial consulting firm CDR that has enjoyed $1.4 million of business from the state.
Richardson put the nation first, recognizing that the investigation could take months impeding his ability to get any work done as head of the Commerce Department. An unacceptable scenario at a time when the new administration must work quickly and win the confidence of the American people.

Richardson said he will prove his innocence, but in this moment he has to put the country first. He offered Obama his continued support until he is cleared. The president-elect said he accepts Richardson's decision.
Richardson, who is Latino, was U.S. UN ambassador, energy secretary under Bill Clinton and has shown prowess in helping mediate issues involving Cuba, Iraq and Sudan.
We hope that if he is innocent it will be proven sooner rather than later. This investigation is impeding the new administration in its quest to make important decisions as soon as possible after Obama takes office.
My question is why did this investigation come up so close to Obama's inauguration? Is this an attempt by prosecutors to take political advantage of the beginning of the new administration? I hope that LAW would be used, not for speculation, but instead by addressing known criminal actions.
Time will tell .