The prosecutor eventually asked the judge to acquit. For which the judge gave her credit. But I don't understand why she prerssed charges in the first place; wa

The prosecutor eventually asked the judge to acquit. For which the judge gave her credit. But I don't understand why she prerssed charges in the first place; was she so unfamiliar with the evidence that she was going to have to present, that she didn't realize it was full of holes until it came to court? There's a missing backstory here. I wonder whether the case was prepared by a junior, and this prosecutor barged in and decided to take over at the last minute, for the sake of personal glory. I can't see why she deserves the judge's approval.