Possibly, but it is very unlikely that it will be dismissed automatically. You will need to fight for it. Start with a Pitchess motion. The purpose of the motion is to obtain information. Then take that info and determine your next step. Lawyer up for best results.
The response above is not intended as legal advice since it’s impracticable to provide thorough, accurate advice based upon the query without additional details. It is highly recommended that one should seek advice from a criminal defense attorney licensed in your jurisdiction by setting up a confidential meeting. Moreover, this response does not constitute the creation of an attorney-client relationship since this message is not a confidential communication because it was posted on a public website, thereby publicly disclosing the information, which is another reason to setup a confidential meeting with an attorney.
Can it be? Yes. Will it be? That's impossible to say.
If the prosecution thinks they have enough credible evidence to go forward without the fired officer and/or having to rely on their report or investigation, they continue to prosecute.
Onlybyourbsttirney can assess the impact of this officer's issues on your case.
The above answer is for general information only and is based on the information you posted. Every case is fact dependent, so to get a thorough analysis of your situation, you will need to consult face to face with an attorney licensed to practice in the jurisdiction where the incident took place. Do not conclusively rely on any information posted online when deciding what to do about your case.
You need an attorney to file a pitches motion. A pitches motion will force the police dept to turn over the information you need to discredit the officer's testimony. Contact an experienced attorney right away.
As my colleagues have pointed out, you need to obtain the information about the officer. Officer employment records are not readily obtainable and require a Pitchess Motion to be filed with the court. An attorney may be essential in getting the information.
There are many questions before anyone can give you an educated guess, (and it will be a guess as the District Attorney is the one who will decide to dismiss or to continue with the prosecution). How do you know the officer has been fired for "misconduct," and what was that misconduct? What are "bad repts," (It may be better to communicate in full words, as sometimes these abbreviations are difficult to decode)?
It is unlikely that the DA will dismiss the case outright unless there is tangible evidence that this officer was less than credible in your case. In any event, as the others have said, filing a Pitchess motion is the next indicated step. Your attorney should know how to do this. If you do not have a good attorney, get one.