I am not sure about the question of "misconduct". If you are asking about police misconduct, I am not seeing any from what you provided. If you are speaking about your potential misconduct or criminal exposure, that will depend on the statements of others involved in the case. PLEASE find a very good criminal defense attorney to assist you with this. "A" having his backpack in your trunk is very defensible if handled properly. Pricing is very individualized to the attorney. If you can't afford an attorney, work closely with your public defender. You should be cleared of this allegation if it is as you reported here. Lastly, do not talk about the facts of the case in an open forum from here on out.
Because you were in the car with drugs, you're deemed to be in constructive possession. You will need to establish that they weren't yours and that you had no knowledge of the drugs. You'll need good defense counsel. If you cannot afford a lawyer, you can ask that an attorney be appointed to represent you.
1. Stop answering police questions other than your name, address, phone number. You can also give driver's license, registration, proof of insurance. 2. Find experienced criminal defense counsel in your area without delay.
An attorney can take prompt steps to see that evidence such as audio or video recordings of the stop is preserved, instead of erased or destroyed.
It is possible that the search warrant was unlawfully obtained. If the lawyer sees a basis, he or she will file a Motion to Suppress claiming illegal search. If that succeeds, the case would likely be dismissed, because of no evidence of drugs remaining.
If that motion does not succeed, you have a fine defense at trial. However, fine defenses can lose. You increase your odds of winning by hiring and paying experienced criminal defense counsel. At trial, the prosecution has the burden of proof beyond a reasonable doubt of all elements of the crime. One of the elements is that the possession of drugs be "knowing." If you did not know there was a controlled substance in your trunk, then you are not guilty. The prosecutor must prove to the jury that you knew it was there. This proof will usually be stronger for the prosecutor if they can present testimony to the jury claiming the defendant said this or that. What a person said can be twisted around by clever or dishonest police officers. Silence is harder to twist around.
You and I do not have an attorney-client relationship formed by our communications on this website. Comments made by me on this website are general advice based on partial information. You should not rely on any advice given without first hiring a lawyer in the area where the case is pending, and providing that lawyer with full information.
I agree with the other answers given and wanted to add something. You do not explain why the police stopped the car in the first place, but an experienced criminal defense attorney may see a basis to challenge the stop and as long as there is not other evidence, such as a statement from you, it may be possible to challenge the evidence seized and get the case dismissed or charges reduced.
Every lawyer has their own way of structuring fee agreements. Many, like myself request a certain amount as an advance fee desposit and then charge for their time hourly, requiring that a minimum balance always be kept in trust. Find the attorney you want to hire and discuss how they wish to structure the fee agreement with you.
I am not your attorney and cannot give you legal advice.