I have been practicing criminal defense for just about 21 years. One of the first lessons taught to defense lawyers is when you get a great piece of evidence or information, you do not share it with the prosecution until trial. Why? Because, especially if it is a problem with something an officer has said in his report (like an impossibility - there is no S curve where he says, etc.), then the State will "fix" it. Similar with other witnesses. If it can be "fixed", it will be - period.
How would this happen you ask? It is called woodshedding. I've already disclosed that I have never been a prosecutor but my understanding is that the prosecutor (person to whom you disclosed your great hose for their fire) talks to the witness & says something like, "hey - did you realize there is no S curve where you said. Could it be you made a mistake & were talking about the S curve a mile away." Witness, "oh yes - that must have been a typographical error when I wrote the mile marker number." . . . or something like that.
My last trial had a great piece of evidence. (Well, it would not have been as great as I thought had the State bothered to disclose Brady / exculpatory evidence because I would have had some impeaching evidence from their own file but, that is another story.) Anyway, my investigator attempted to call the brother of the c/w (complaining witness - girl who was making the accusation) to interview him, only to find that the c/w had the phone. Moreover, she was just happy as a peach to run off at the mouth of what she claimed happened.
Without going into details, her claim to the investigator was NIGHT & DAY different from her prior claims: new manner & means, new location, craziness claiming everyone was in the room right next door & wide awake! YEAHHHHHHHH. Wow.
Normally I would have just gone to trial & stuck it up her nose sideways, but there was a lot at stake here. Not only was my client's freedom at stake, but he loves his family & this was tearing a rift in the entire family. Moreover, there was going to be some graphically, embarassing details about 2 girls that would come out - and I truly did not want to embarass them. (Kids some times do things that no one else knows. There is no need to elaborate but I really do have a heart, and I did not want to cause unnecessarily embarassment.)
I fought with myself about disclosing this. I don't disclose, but there were these other issues. I finally had a talk with the prosecutor who led me to believe that if the girl really said X on the tape, then he felt he could not convince a jury beyond a reasonable doubt. I knew she said X, and took his words to mean he would dismiss. SO, with the client's understanding, I played the audio. (It is always better to get a dismissal than a trial - trials are NEVER a sure thing - especially when the allegation is sexual assault of a child.)
The prosecutor took detailed notes & disappeared for a meeting with c/w. My investigator even let c/w hear the beginning which had her voice. (She had denied to prosecutor having a conversation with investigator WHO FULLY IDENTIFIED HERSELF AS INVESTIGATOR FOR THE ACCUSED.)
He comes back - trial. He cannot explain why but I can - he let the father who is a vindictive jerk, who knew nothing about all the things going to come into play in this case, intimidate him. Rather than "do the right thing" with information I disclosed, suddenly at trial the c/w remembers talking to my investigator & saying the things (that the prosecutor had detailed notes on.)
I got a hung jury 8 to 4 for not guilty. (2 jurors lied - they had family members who had been victims & failed to disclose it although this question was specifically asked.) See, the prosecutor was right when he said that if she says X, then I can't prove the case beyond a reasonable doubt - and he couldn't. (They dismissed after trial.)
But, I re-learned my lesson - I will not share again. Nope. That was it for me. I knew better but I was trying to protect HIS c/w and another witness from massive embarassment but the prosecutor just didn't get it. I get it though - I'm done with sharing after that. From now on, expect to hear my good stuff during the trial. I may be an old fool, but I won't be that foolish again.