It looks quite interesting, although the fact that the father established in his will that he was going to be murdered and that whoever finds out the truth of his death is the beneficiary of all his inheritance seems too far-fetched to me (Keep in mind that one of the basic elements that must be taken into account in all my ideas would be their credibility).
If it were at least half of the inheritance, it would be more realistic with a clause like this ("in case my death is unnatural or shady, whoever manages to solve what happened to me will be the beneficiary of half of my assets"), well it is assumed that there are more relatives of him (For example, if the father suspects that he is going to be murdered for something, he should not rule out the possibility that his own son wants to do it for the inheritance; therefore, in that case the one who discovers the reason for his death would not be the son, but another person).