Rev A: Added sentence to end of 1st para.
There are so many facets to what organized Satanism is trying to accomplish with its apparent tool Giuliano Mignini that new ones occur to me often, and I forget ones I've already recognized. However, one of the biggies is to keep the subliminal belief in "black masses" and similar sordid, dark fantasies alive. The nearest reality to these fantasies is an initiation into black magic, assuming they haven't changed significantly in the last couple of thousand years. Based on Rudolf Steiner's clairvoyant perceptions of such events from the time of Christ, each degree of initiation required a murder in a very quick, precise, and grisly manner, in order to generate certain spiritual forces. Naturally, the details nave not been revealed, but based on Steiner's description, Guede's sloppy murder-rape hardly qualifies as a black magic initiation, although I suppose it's possible that he believed that it was such an initiation. Perhaps his crime spree leading up to the murder was intended as preparation for his "initiation." It's really impossible to be certain. However, there is no doubt that such hideous torture-murder, done with the "right" attitude, could contribute to demonic possession, even though it's unlikely to be repeated, at least very often, in the absence of war or other types of chaos where the evidence of such activity could be concealed.
But in order to keep these fantasies alive, there has to be a minimum amount of "evidence," and this was a likely motive behind the Monster of Florence killings. Obviously, they get a lot of mileage out of each of these murders, so a lot of thinking goes into how they're going to respond. So, I suspect that Mignini planned to use Lumumba, Knox, and Sollecito as the scapegoats even before Kercher was murdered.