Minn. Stat. § 595.07: CONVICTED PERSON AS WITNESS.

Every person convicted of crime shall be a competent witness in any civil or criminal proceeding, but the conviction may be proved for the purpose of affecting the weight of the testimony, either by the record or by the convicted person's cross-examination, upon which the convicted person shall answer any proper question relevant to that inquiry; and the party cross-examining shall not be concluded by the convicted person's answer thereto.