that is montana statue for "theft". i dont know if there is similar laws in every other state....but I am willing to bet there is. And if the cops actually said you can keep lost or misplaced property i would not want to live in that town
i am pretty sure it is illeagal in all 50 states to knowingly obtains or exert unauthorized control over property of the owner and, has the purpose of depriving the owner of the property, purposely or knowingly uses, conceals, or abandons the property in a manner that deprives the owner of the property or uses, conceals, or abandons the property knowing that the use, concealment, or abandonment probably will deprive the owner of the property.