i had the opposite happen , The defendant was going with not guilty , when his lawyer saw the evidence against him , he asked for a minute spoke to his client and they changed he plea to Guilty.
I have a friend that kind of did something illegal. The plaintiff midway through trial recanted their testimony and gave up prosecution. The prosecutor continued to get the maximum sentence for my friend.
Even though he wasn’t innocent, but wasn’t necessarily guilty, he still spent 4 years in prison because the prosecutor wanted a win.
Even while in prison the plaintiff wrote letters saying he should not be in prison. Doesn’t matter.
Speaking as to Canada, but I think it applies generally. Yes a prosecutor can do that. They have discretion, and it’s not a prosecutor’s job to get people convicted. It’s their job to seek justice.
Generally there aren’t too many surprises at trial, lawyers will have gone back and forth and argued over evidence and admissibility and given will-say statements of what their witnesses will be testifying to, in the weeks/months before trial. There may even have been earlier appearances before a judge to get rulings on evidence or procedural matters. So it won’t be too common for a prosecutor to be surprised by new evidence mid trial. But if they are, they can call a halt to things, or ask for a break and review outside the courtroom, etc.
I’m a lawyer but I don’t do much criminal law, just low-level stuff on the side. I’ve heard of one local case in the last few years where the trial fell apart halfway through. I don’t remember the circumstances, but it wasn’t a scandal or anything. Crown left, came back and directed a stay of proceedings. It happens more often in family trials where halfway through the lawyer suddenly has to totally re-evaluate their position. Witnesses in family cases can be wild.
There are many cases where it’s later discovered that the prosecutor hid evidence showing a person was innocent.
Because politics: see Flynn