To make anybody accountable, the shields have to come down. The senior officials who oversee these agencies should be brought to justice immediately, not tomorrow or day after. They are deliberately obstructing justice in every step of the way. Police, federal or local, aren't laying any criminal charges, although these are within their knowledge. Politicians would not do it as they always hide behind these shields.
People have to do it.
Having somewhat verbalized these, it has to be carefully noted that people themselves working in these agencies or institutions may not be all hoodlums or goons. Mostly they are just average decent people, but are being constantly coerced to go along with the power that dictates the agencies. Many a time, some of them had tried their best and lost their jobs. Neither the watchdog agencies, nor the news media came to their rescue. Elected officials have very little control over these agencies.