Neither an American or a lawyer, but
according to this Mo. lawyer:
- challenges are heard by a jury (imagine how normies would react to Dave!)
- the jury has to determine if the will is otherwise valid and the testator was aware of the „natural objects of his bounty”
- if yes to all of these, ”then the usual remaining issue is whether there was such undue influence on the decedent as to cause the jury to conclude that the free will of the decedent was overpowered and destroyed, resulting in the decedent signing a will that otherwise would not have been signed.”
- if a will is invalid, assets are distributed via the usual principles of intestacy.
Dave could argue he is a natural object of Joe’s or Mary’s bounty and that Jeff and Andy overpowered them, leading to his disinheritance. The cool thing is that in terrorem clauses are enforceable in Missouri - basically, you challenge, you lose whatever you would have received under the will. So any competent lawyer would advise Joe and Mary to get some proof they are mentally competent to make a will, leave him a sum of money which isn’t a large chunk of the estate but would be helpful to him (say, ten grand) and include the reasons they’re giving him only a small amount (such as the fact he’s got an arrest for stalking his parents, along with his other crazy shit), and back it up with an in terrorem clause. He challenges, he loses even the small amount. Checkmate.
I suspect that as
@Nanashi no kiwi said, some trust might be set up so he isn’t annoying decent homeless people, although who would serve as trustee and become Dave’s new target is a puzzle
