When a bank is robbed, the FBI swoops in. When a major bank loses $2 billion, other agencies take the lead. But in the case of Jamie Dimon and JPMorgan Chase, the FBI is investigating there as well in the wake of its stunning loss, which has triggered investor lawsuits. Bank regulation remains a contentious issue, but what about criminal liability? Should CEO and Chairman of the Board Dimon be brought up on charges? Should he and other bank executives face jail terms?