S.D. Codified Laws § 10-1-6.1
The secretary of revenue may appoint up to five special agents to investigate violations of any of the provisions of title 10, title 32, title 35, and chapter 37-10, and to enforce any statutes that the secretary is given the power to enforce. The special agents have all of the powers and authority of law enforcement officers while performing duties pursuant to this section. The special agents appointed by the secretary are subject to the requirements of §§ 23-3-41, 23-3-42 and 23-3-44, shall cooperate with local law enforcement officers who have primary responsibility for law enforcement in their jurisdiction, and shall keep those officers informed concerning investigations within those officers' jurisdiction. The special agents appointed by the secretary pursuant to this section are class A employees for retirement purposes.
SDCL 10-1-6.1