Does the govt have a responsibility to protect him?

The constitution prohibits the government from using cruel and unusual punishment. Putting a despicable prisoner in a position where they will undoubtedly be subjected to cruelty by other prisoners is cruel and unusual punishment if there is no chance that they will be treated as a human.

For instance, Jeffrey Dalmer was murdered by another prisoner. Was anyone surprised when that happened? No! A person would have to be quite gullible not to know what would happen when someone like Jeffrey was placed with other prisoners. The one thing our Forefathers could not have predicted though is our use of capital punishment. The forefathers would have expected someone like Dalmer to be executed shortly after he was decidedly convicted. Locking them up for life or taking twenty or thirty years to convict someone when their guilt is obvious invites "fellow prisoner justice."

 

I agree with @HatedByAll. His sin is no different than any of the other inmates. The government should prohibit other inmates from practicing their own form of (in)justice.

I also think the entire "justice" system is entirely unbiblical, but that's a different discussion for a different time

 

Yes, the idea that the prison guards "allow" prisoners to be molested by either guards or inmates is a national disgrace. I do not know if the practice is as widespread as indicated by our TV shows, but I hope not. I do know that it happens at least to a limited degree.