This is what law school DOESN’T teach you. Prosecutors have absolute immunity from CIVIL liability due to the SCOTUS Rehberg v. Paulk decision (linked).
But even lawyers are misunderstood; this doesn’t protect prosecutors from CRIMINAL liability. So how are all these prosecutors getting away with their white collar crimes (Mike Nifong, Ken Anderson, etc. etc.)?
As I state in the article, a prosecutor’s criminal conduct in the context of prosecuting a case would never be prosecuted by other prosecutors. It would set a “bad precedent” for the brotherhood. It would open a Pandora’s Box and they’d be prosecuting the hell out of each other.
If it was shockingly egregious criminal conduct while prosecuting a universally beloved public figure (like Mr. Rogers or Joe Montana or similar), you might see criminal charges in relation to impeachment proceedings undertaken by a legislature, but although that is possible it isn’t likely.
Now if a prosecutor did something horrible to children or copyrighted materials or something he might be prosecuted criminally for that, only if it had nothing to do with his work.