Minn. Stat. § 548.05: TREBLE DAMAGES FOR TRESPASS.

Whoever shall carry away, use or destroy any wood, timber, lumber, hay, grass, or other personal property of another person, without lawful authority, shall be liable to the owner thereof for treble the amount of damages assessed therefor in an action to recover such damages. If upon trial, the defendant proves having probable cause to believe that such property was the defendant's own, or was owned by the person for whom the defendant acted, judgment shall be given for the actual damages only, and for costs.