Mignini KNEW that Knox and Sollecito were innocent all along, as proven by the fact that he buried evidence of their innocence, such as by telling the police to "accidentally" destroy the hard drives' electronics and to refuse to have them repaired and examined. He's not insane, but evil.
We're told that Mignini is a "conservative Catholic," who got his "theories" (fantasies) from another "conservative Catholic" who supposedly channeled a dead Catholic priest and "discovered" a supposed highly secretive occult order whose members perform rituals which are indistinguishable from incredibly sloppy murder-rapes, which would tend to draw attention to the "occult order." Yeah, that sounds really logical.
In fact, his "psychic" was probably a literal witch, and the dead priest probably symbolized the rest of her group with whom she concocted these lurid fantasies to be superimposed on real-world murders (perhaps committed by actual Satanists), in order to allow innocent people to be blamed and put through hell.
Note that the "Christian" Mignini has also indicated sympathy with Rudy Guede, the actual killer (who left a great deal of physical evidence) by calling him a "poor unfortunate," while almost simultaneously demanding life in prison and six months of solitary confinement for Knox, despite having no physical evidence that she committed a crime. (He probably demanded super-harsh punishment for Knox partly to convince us that he has some inadmissible proof of her guilt, just as Cheney pretended to have classified proof that Saddam had WMD. By ACTING as if he knew, Mignini hoped to sway the jury.)
Some people supposedly suspect that Mignini was behind the lenient treatment given to Guede before he murdered Kercher. So, the question arises: is Guede a member of organized Satanism, and was his crime-spree (which the police ignored) intended to culminate in a rape-murder as a sort of "initiation" into Satanism? Did Mignini plan to pin it on Knox, Sollecito, and Lumumba even before it occurred? Perhaps they waited a while to arrest them to avoid the appearance of being preordained.
Actual Satanism intends to create a global Orwellian fascist dictatorship (similar to Italy's "justice" system) in order to drive the human spirit out of the world through oppression, into a realm of fantasy and escapism ruled by Lucifer , whose influence is intertwined with Satan's, but who is actually a different being with a different influence. (Satan oppresses without allowing the possibility of physical escape, while Lucifer seeks to cultivate escapism. Amanda Knox's ordeal of being caged and abused, while longing for her former happy life, epitomizes this dual influence.) Was Mignini trying to obliterate Amanda Knox's self? Why not interrogate this criminal?
Satanism consists of three main aspects: a) gratuitous lying; b) loveless Dionysian "wild abandon"; and c) gratuitous, repetitive ("ritual") and escalating cruelty, a.k.a. SRA. Dionysian abandon for purposes of Satanism typically takes the form of orgies. SRA takes the form of anything from rudeness to torture-murder. Advanced SRA typically takes place in the guise of an insane "war" based on lame lies ("banality of evil"), although it also takes place in the form of a global economic crisis based on such lies.
The purpose of Dionysian abandon is to allow a certain type of quasi-human Satanic being to take possession.  These beings impart a contemptuous, Nietzschean "superman" attitude. Nietzsche, a channel for Satan, called these beings "expansive energies," which are not listed in Maslow's hierarchy. Satan would naturally want us to believe that becoming possessed makes us superhuman, when it actually makes us subhuman. If you read Nietzsche with this in mind, you can see how Satan seeks to trick people into becoming possessed, and to define a class of "subhumans" with "slave morality" who can be subjected to advanced SRA with impunity by "supermen."
The purpose of SRA is to align the perpetrator's will with the will of destructive Satanic beings known as demons. This process can be compared to the process of "re-keying" a lock to go with a certain key. Once the "lock" (person) fits the "key" (demons), the latter quickly swarm into the person's soul and latch onto it, and the person is no longer a human, but a cunning predator, a being of destruction, similar to a psychopath. Note that Aleister Crowley, in The Book of the Law, advocated murder, torture, and torment.
"Luciferianism," as implied by the preceding description of Lucifer's influence, consists of devising schemes to cultivate escapism from Satan's oppressive rule. So, a "Luciferian" would be someone who contributes to the many fantasies into which modern man "escapes," with the intent of inducing mass-escapism. One form of "escape" is to dwell on lofty concepts, which can lead to Luciferic possession characterized by a constant state of "rapture." Actual occult orders (white path) take measures to prevent this from occurring in their students.
It is obvious to me that Amanda Knox's ordeal was SRA directed by Mignini, whose actual game was to use the power of his office to superimpose his lurid fantasies onto actual humans, in order to "demonize" them and "justify" subjecting them to SRA. Note that Knox recently claimed on CBS 48 Hours (October 8th) that a high-ranking prison official tried to get her to have sex with him, indicating a Satanic orientation, because such sex would be loveless. Knox obviously would not have loved him, and he obviously cannot "love" anyone unless they are under his thumb, if at all.
Since Mignini claims to believe that orgies can lead to such crimes, why hasn't he gone after the orgies which reportedly take place in Perugia? Might that be because orgies are one of Satanism's main recruitment tools, and Mignini isn't interested in preventing actual Satanism, because he is an actual Satanist? All the physical evidence supports this theory.
Rev A: added Note 2.
 In ancient times, Dionysian abandon was intended to evoke a fading form of clairvoyant consciousness, described from a materialistic perspective in The Origin of Consciousness in the Breakdown of the Bicameral Mind, in which mankind literally communed with the gods, who provided guidance. The reason this perspective is at odds with Darwinism is that it's true, whereas Darwinism is a lie concocted by the Cult of Isis and attributed to Darwin, who is buried in Westminster Abbey, oddly.
 This is a reference to the 8th Sphere.