I am seeking a starting point on locating information about an incident that happened in my father's family while they lived in SD. Basically, a nanny/baby sitter poisoned with lye, two of his siblings. One lived and one died from this incident. I am not sure exactly where the incident occurred, but they resided in Beadle County until moving to Oregon in 1911. Estimated this happened between about 1898 and 1901. Supposedly the nanny was prosecuted.

I do not have any name of her. The victims were Carl Max Mueller/Muller and Ernest (?) Mueller/Muller. Ernest (not 100% positive on name) was the baby who died. Both were children of Adolph and Bertha Mueller/Muller. Have found no birth record in the on line search of "over 100" records.

Any ideas would be helpful.