I recommend being very friendly with the claim procedure. Trying to sue under those circumstances would be problematical because the governmental personnel did not appear to be negligent in the performance of their duties.
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I don't practice in Washington, but I believe every State has a statute that allows you to sue the government for certain torts, when they cause damage that arises from acts committed in the course of certain normal activities. This potential liability is similar to the kinds of claims that are made against ordinary people and businesses. For example, if a city employee causes a car accident, the city government can be sued as though it were any normal employer.
Damaging your items may be one of those torts for which a government agency can be sued, based on the idea that if you had left the computers with a repair shop and they were damaged that way, the shop would be liable.
However, suing for the hardship caused by an investigation or prosecution that was later dropped does not necessarily mean the government is liable. The government is generally immune from liability for acts done in their official capacity (like arresting and charging people), unless you can show that it amounted to a false arrest or malicious prosecution, or some other civil rights violation. This is a high standard, and requires more than merely being exonerated later. You would need to show that they had no probable cause to make the arrest and/or charge an offense at the time.
Please note that this is just a general statement based on what you've said here, and you should certainly consult a litigator about the facts of your particular situation.