
Quoting
cdwjava
Laws vary by state as to how agencies may dispose of what kind of property.
What state are you in?
In general, if the police have something in their possession without an owner, they can dispose of it as the law and agency policy see fit. Very often there is a lengthy time period the property must be held. If it is found property it might be held for as little as 30 days whereas some items of possible evidence might be held indefinitely or at least until after the time for appeals have passed when a conviction has occurred. Many items can be released to a legal owner after documenting and photographing the item(s).
But, it all depends on state law and the individual agency's policy on property.