Hi,
Please, what's the meaning of the underlined part?
"John Taylor is a prisioner, guilty as charged."
Consider this scenario,
John is arrested by the police.
After the police question John, they are sure that he robbed the bank.
The police charge him with bank robbery. This means they do all the official paperwork that means John has to appear in court.
Now, here's the point. Just because John has been charged by the police, it does not mean that he is definitely guilty. Maybe the police have made a mistake, and John is innocent.
However, the writer of your sentence is telling us that John is guilty of the crime that he has been charged with. We don't know how the writer knows this. Perhaps he is writing this after John has gone to court and has been found guilty.
Best wishes, Clive