Is it possible for this prisoner to get a personal television, a transfer, a suit, or a lesser sentence?

It is possible but it may need the approval of the governor if he is in on a State conviction.

Typically the prosecutor's office can have the authority to appeal to a parole board to effect a lessened sentence for an inmate based upon their willingness to assist the prosecution in the criminal prosecution of another person. Be mindful however that this is rarely done for current inmates, but is often offered for persons who seek immunity from certain criminal charges in exchange for their own testimony at trial on behalf of the prosecution.

One time I was setting as a temporary judge in a civil case there a prisoner had had his stereo damaged while the prison was relocating him. I was stunned that the prison admitted that they had broken the stereo and that a prison would have one in his cell. So I guess TVs of not any different than stereo sets. I do not think it is probable that the prison would let an inmate ware a suit.

In general, deals in exchange for leniency are done before sentencing, but if it has to be post-conviction for your plot to work, then. Sure. All those things are potential. Some more realistic than others though. Lets start with where they are housed. Could they offer information in exchange for a transfer? Possibly. But - the DA or judge doesn't dictate where a person will serve their sentence. Thanks typically up to the department of corrections to house an inmate where they feel it inappropriate base on their offense, prior history, history of assault on guards, rules violations, etc. Could the info your guy has be enough to have the cop/DA/judge step in and see if corrections would listen? Yes. It would take cooperation between a number of agencies. Regarding the ability to possess normally forbidden items (many prisons will allow an inmate to have a TV currently) such as civilian clothes. Although anything is possible, it would be such a security risk for them to allow an inmate to be in civvies that it seems unlikely. And even if they would, why would your inmate want a suit? He would instantly be a target of other inmates since he is getting special treatment, etc. And finally reduction in sentence. This will largely depend on your fictional state. I your guy was convicted in California of murder for financial gain (aka paid hit man), he would get life without the possibility of parole if he didn't get the death penalty. Even if a judge wanted to reduce that sentence, that is the mandatory sentence under the law. If your fictional jurisdiction had him serving a "something to life" sentence, it could work out that the prosecutor could put in a strong request to the parole board for your guy. Or not oppose his release. For that matter, depending in his ha your guy has to offer, could the plot include a pardon from the governor? Let me know if you have further questions and good luck on the writing. Pardon any typos, posted via mobile device.

It's fiction, you can write whatever you want. This forum is for real people with real problems.