I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear about your situation.
The owner of the vehicle may be able to sue the police department and the officer for a civil rights violation where the stop and search were based on the driver's race and not probable cause. A stop is only legal if the police officer witnesses a traffic violation or has reason to believe the officer has committed another crime (like if they were chasing someone from the scene, or if they ran your plates and found a warrant). When a stop is illegal, the search is ALWAYS also illegal. Even if they had a reason for the stop, they can't search the vehicle unless you consent, they're arresting you (based on probable cause) or they have probable to believe there is contraband or evidence of a crime inside. A person can move to suppress evidence illegally obtained when the search was invalid, the initial stop, or both. Both of those can also give rise to a suit for a civil rights violation.
Slander is an untrue statement of fact made to a third party that tends to harm the reputation of the person about whom the statement is made. The driver couldn't sue for an untrue statement about one of his relatives unless is also affects HIS reputation. The person they were talking about could sue the police officer personally for the false statement, but the police department typically would not be responsible. This is not a civil rights violation - it's a regular defamation case. Civil rights violations occur when someone infringes upon a right guaranteed by the constitution, but defamation of character is not in the constitution. That's a statutory construct, meaning that it's an issue of state law. A 1983 civil rights action is a federal case.
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