8. Fred Berg executed a will in December 1997 in which he named one of his nephews, Roger Berg, as his sole heir. Roger was acting as Fred's attorney-in-fact at the time but was unaware that he had been named the sole heir in Fred's will. Fred had a long history of mental health issues dating back to his discharge from the US Army in 1943. He had been institutionalized on several occasions, subjected to a bilateral prefrontal lobotomy in 1950, and declared incompetent by the Veterans Administration in 1967 for purposes of insurance and disbursement of benefits. Fred died in November 2006, leaving an estate totaling more than $500,000. Roger disclaimed his interest in the estate and stated that it should go to Fred's surviving sister Helen. Fred's niece Carol Opdahl objected to Fred's will and sought a declaration of intestacy. Opdahl sought an equal share of Fred's estate and claimed that he was incompetent. Her claims were based on Fred's belief that a fictitious person was his father and on the facts that he did not know the amount of his estate and had been declared incompetent by the Veterans Administration. Opdahl also claimed that Roger exercised undue influence over Fred. Roger responded that Fred's delusions never affected his testamentary capacity and that the Veterans Administration's declaration was silent as to Fred's ability to make a valid will. Furthermore, Roger claimed that he did not exert undue influence in order to gain access to Fred's estate as he had disclaimed his interest in favor of Helen. What is the standard for determining whether a person possesses testamentary capacity? What evidence would be relevant to such a determination? Can a person be declared incompetent with respect to some activities while remaining competent to make a will? Can a person be held to have exerted undue influence when he or she later a disclaims any interest in the estate? [In re Estate of Berg, 783 N.W.2d 831 (S.D. 2010).]