"Charities, The Foundation of Madoff's Scheme," Fortune. He needed long term money; foundations needed a nice, reliable 12% to cover payout, administration, and inflation. What personal liability foundation trustees may have for the losses remains to be settled, presumably by regulators and the courts.
Madoff on Youtube explains how the market works. "It impossible for a violation to go undetected, at least for long." If anything, he suggests, the regulatory environment has become a bit onerous.