Sounds like you did not get the full story or the cops are let's say not the brightest. If the stuff had been found just out, he could easily be charged. If the stuff was found on another, he should not have been charged. Hire a lawyer to represent him and do not ask him any questions which could make you a witness.
It depends on what kinds of statements the kids made to the cops. Hire a ticket attorney to handle this for you. He will be able to get your son some type of dismissal and help clean up his record.
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I agree with Ms. Henley and Ms. Jaggers that this is a case where your son needs a good lawyer.
I am puzzled from the facts you give about why the officers thought they had authority to search the vehicle and it's occupants. Perhaps there is a bit more to the events.
At any rate, I suggest you get your son a good criminal defense lawyer.
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