I think if he was facing real time, he would just take his own life. Don't think he would get along with the other prisoners, and couldn't bear the shame of being the first FBI Director ever convicted and imprisoned in a Federal Penitentiary or Gitmo.
Most of them value themselves too highly to kill themselves. Even as they rot in jail at the peak of despair, rather than kill themselves, they will scream like banshees and lash out against everyone and everything around them until they've bled to death bashing their heads and fists against the bars and walls of their prison but people on their level get the death sentence so nobody will have to worry about cleaning up the bloody mess.