Minn. Stat. § 388.14

The county board may set apart yearly a sum, not exceeding $7,500, except in counties containing cities of the first class, where the sum shall not exceed $10,000, as a contingent fund for defraying necessary expenses not especially provided for by law, in preparing and trying criminal cases, conducting investigations by the grand jury, making contributions to a statewide county attorney's organization, and paying the necessary expenses of the county attorney incurred in the business of the county. All disbursements from such fund shall be made upon written request of the county attorney by auditor's warrant, countersigned by a judge of the district court. Any balance remaining at the end of the year shall be transferred to the revenue fund.