S.D. Codified Laws § 23A-9-3
Current with legislation signed by the governor on or before 3/6/2024
If prior to or during trial, a party learns of an additional witness whose identity, if known, should have been included in the information furnished under § 23A-9-1 or 23A-9-2, he shall promptly notify the other party or his attorney of the existence and identity of such additional witness.
SDCL 23A-9-3