Considering the Knox inquisitor Mignini seems to know that orgies can lead to bloody murder, it seems that he would at least do something to warn people about them. But the fact is that he knows his claims about what happened in the Knox case were never true, and that his fantasy doesn't fit into the real world. Note that the media overlooked the huge differences between his bogus version of possession, and the bogus Vatican-Hollywood version. Neither is correct.
Satanic orgiastic activity (i..e. LOVELESS abandonment to one's lowest impulses, where there is no love, but just a selfish pursuit of gratification, i.e. treating others as objects for self-gratification) leads to so-called "Jupiter man" possession, which has an element of animosity toward humans and animals, but tempered with the influence of highly intelligent higher-level Satanic beings who see the big picture, and who wish to keep their influence secret above all else, in order to pass their puppets off as regular people. If, in the middle of an orgy, someone becomes possessed in this manner, they wouldn't do something that would freak people out and frighten them off, because that would undermine Satan's strategy for creating an army of pod people.
So, the notion of someone suddenly switching from sexual arousal to murder under the control of one of these beings is unlikely. However, the Spirits of Darkness, i.e. Satanic angels (more properly, Angeloi), are another matter entirely, because they use people to accomplish some short-term goal, and then discard them, as in the Andrea Yates case (go here, scroll down to Yates-related links). So there is a possibility that they would cause something like what Rudy Guede did. Rudolf Steiner said that they "egg people on," and Guede was known to hang out near the apartments where Meredith and Amanda lived. Perhaps they started "whispering in his ears" long before he murdered Meredith. Perhaps they drove him to do what he did, knowing that Meredith would return while he was burglarizing the place, and that Rudy would panic and give them an opening. In any case, if someone committed such a crime due to possession, the SoD's would be the likely culprits, and not the other sorts of beings mentioned here. It's also possible that Guede has some sort of a psychopathic disorder.
Mignini's scenario, assuming it's not caused by the SoDs, would probably be a sort of amalgam of the two types of activities which are intended to lead to two different types of possession. Besides the aforementioned orgiastic type of activity, there's SRA, which consists of escalating, repetitive gratuitous cruelty intended to induce demonic possession. The more advanced forms such as "enhanced interrogation," torture, and murder are for the most part perpetrated in the course of "wars" such as the "war on terror." Furthermore, when someone does become demonically possessed, their drive to damage and destroy the lives of humans and animals is tempered with a cunning intended to make Satan's tool as useful as possible. If demonic possession caused the sorts of behaviors described by Mignini or the Vatican, they'd soon end up dead or in prison, which would make them useless as tools. So, they would kill and destroy only when they have a plausible cover story, such as the "war on terror," which is almost pure destruction. (The majority of the soldiers in the US military are among the victims in this "war," along with their families and their communities, which are bearing the financial burden.) I suspect that the recent "black ops" invasion of Libya is a good example of this destruction being perpetrated under a smokescreen; intelligence agents acting as reporters provided a smokescreen, under which a slaughter, including beheadings by NATO soldiers, ensued. The end result was a lot of dead Libyans and massive destruction to their life-sustaining infrastructure, which will cause death and misery for a long time. It also had a "hands on" aspect which I consider to be a hallmark of demonic possession. The demolition of the WTC, however, might have been done with a more detached attitude, such as that of a black magician. So, there are a lot of subtleties, and I think that a good psychologist would be more qualified than myself to discern between these sorts of possession, or to distinguish between possession and the ice-cold egotism of a black magician, if there were any who would take it seriously enough, and risk their career, to study it. So, I doubt it's going to happen, and I encourage those who read this to take it with a grain of salt, in the unlikely case that they don't already do so.
But my point is that Mignini isn't on a crusade against actual Satanism (the outer circles of which consist mainly of loveless orgies), but a crusade against a fantasy-version (which changes as required), and that this crusade provides him a pretext for perpetrating SRA against those on whom he superimposes this fantasy-version.