Kerik Indictment Expected

The man that Bush chose to be the head of Homeland Security, to protect the elderly, the sick, the very young and the very old from attack, is about to be indicted for things that easily would have come up in a standard background investigation. Why did Bush and Giuliani insist on picking him in the first place? The crimes took place in the late 90s and in the current decade, before he was picked to head DHS.