During several weeks late last year—when some crucial legal decisions affecting not only Bank of America Corp. shareholders but the nation’s economic system were being made—the bank fired its general counsel and replaced him with Brian Moynihan, a business executive who hadn’t practiced law in years. And he wasn’t even actively licensed as a lawyer at the time he was named.

“How were the legal interests of the bank being protected?” asks one source close to a federal investigation into the bank’s actions. “The shareholders who are filing suits against the bank [for failing to disclose certain facts] might want to ask that question.”