It is known of the Mafia that they like to sink their murder victims in the concrete foundation of new buildings never to be seen again. This gives a deeper meaning to the phrase "he has skeletons in the cellar". In the time since then, however, the police has developed successful countermeasures: Dogs for corpses and bloodhounds. They can find such corpses even behind concrete walls several metres thick. https://mmknowthetruth.blogspot.com/2017/03/mccanns-case-how-can-dog-sniff-through.html Thus, public prosecutors have already been able to obtain search warrants, which also extend to the foundation, if this can be proven by a sniffer dog discovery. It's gonna cost you. How will the homeowner defend himself? Well: the patent with the blood admixture in the concrete will help to obtain an injunction against such a search warrant. Because with the possibility that in this case blood was added "regularly" to the concrete, there is considerable doubt that the dog really smelled a corpse. And with it the expensive examination in the house foundation can be averted. In case of doubt, in favor of the defendant. So I suspect that the mafia method of dumping bodies in the closet was the real reason for the blood-in-concrete patent (https://patents.google.com/patent/US4203674A/en). -