Defender is probably good. Prosecutor is what would worry me, given I don't know better than to blindly trust the meme that the average person commits 6 felonies before breakfast.
Defender is a TERRIBLE idea. I can already see the Supreme Court cases down the line:
Defendant was provided a state of the art, 50 trillion parameter, neural network for their defense. The internals of this network are not auditable, but it does not tire, engage in substance abuse, or get distracted, so it will by definition represent effective assistance of counsel, even if for some unfathomable reason it decides to raise the Chewbacca Defense in a Death Penalty habeas corpus petition.
Ok? This is like the arguments that self driving cars are bad if they crash even once.
The question isn't "is the AI giving me the perfect legal defence?" or even "is the AI giving me a defence as good as the best lawyer money can buy?". It's "is the AI better than the public defender that I otherwise would have been given?".
As soon as the answer to that last question is yes (and I have absolutely no idea when that will be), it will be extremely difficult to justify not using it.
What I'm concerned about is that states which are currently skimping on funds for public defenders will just declare some chat system "good enough" as an excuse to get rid of the remaining funding for human defenders.
It will also virtually ensure that the only work conducted on the behalf of the defendant is based on the written record available to the court. Not a single phone call will be made. If the defendant's physical appearance does not match witness descriptions, the system is unlikely to notice. If the crime site does not match the police statement, the system will never know.
And if the cost of prosecution falls then more and more of those 6 felonies will end up prosecuted. The same happened with speed cameras, initially it was to reduce accidents, now it is just another income stream (which I'm sure still reduces accidents, but that's no longer the main reason they are out there).
Defendant was provided a state of the art, 50 trillion parameter, neural network for their defense. The internals of this network are not auditable, but it does not tire, engage in substance abuse, or get distracted, so it will by definition represent effective assistance of counsel, even if for some unfathomable reason it decides to raise the Chewbacca Defense in a Death Penalty habeas corpus petition.