Mignini's investigation resulted in the prosecution of 20 individuals over the following years, on allegations indirectly connected to Narducci's death such as cover-up and side-tracking charges.
The verdict pointed out that as scientific evidence was "central" to the case, there were "glaring defalliances" or "amnesia" and "culpable omissions of investigation activities".
[5] He passed the magistrate's examination in 1979, and worked for one year in Volterra serving as pretore (an investigating judge role which does not exist anymore in the Italian system).
[13][14][15] In early 2002, blogger Gabriella Carlizzi contacted Mignini regarding her theories about Narducci being part of a secret society behind the Monster killings.
[16] Narducci's name had also emerged within an ongoing phone stalking case Mignini was investigating, where some of the conversations they recorded included references to the Monster of Florence and secret societies.
Mignini asserted that the body had been switched twice, and the pathologist claimed to have found evidence that the cause of death was not drowning but strangulation due to a small, isolated fracture on the upper thyroid horn.
[19][20] Mignini's theory involved a complicated conspiracy of 20 people, including government officials and law enforcement officers, who all concurred in covering up Narducci's cause of death.
2006, Mignini summoned American author Douglas Preston for questioning as a person informed about facts related to Spezi's activities.
Preliminary judge Marina De Roberti, on Mignini's request, ordered the men to be held in cautionary custody and not to speak with his lawyers anymore before the first hearing in Court that took place on 11 April.
Mignini refused to surrender the investigation, claiming the Trasimeno Lake shore where the body was recovered was in territory under his jurisdiction.
Mignini opened an investigation against Ubaldo Nannucci and against the Chief of Police in Florence, Giuseppe De Donno, baed on the recording of Canessa's voice.
In 2006, Florence prosecutor Luca Turco, charged Mignini and the head of the GIDES Michele Giuttari with a number of counts, including the forging of Canessa's voice recording, plus a number of counts of abuse of office for allegedly ordering the wiretapping of the phones of various police officers and journalists involved in the Monster of Florence case.
[35] Mignini was charged of being implicated in the forging of a fake audio recording and abusing his powers as he investigated De Donno, and for having wiretapped phone calls of three journalists and two police officers for unjustified reasons.
[38][39] According to Rome-based journalist and author Barbie Latza Nadeau, even if Mignini were convicted, offenses such as this are rarely grounds for removing a prosecutor from office.
[41][42] The Prosecution General of Florence appealed against the decision at the Supreme Court, so factually blocking the transfer to Turin for at least another year.
While the Italian justice system does not prosecute criminal allegations beyond statutory terms through penal courts, Italian Magistrates are still subjected to a judgement also by a disciplinary court of the High Council of the Judiciary (Consiglio Superiore della Magistratura, or CSM) which seeks to find out facts in the merits, even if the Magistrate has already been acquitted of criminal charges on technicalities, or when there is still reasonable doubt.
As part of his summing up in the first Knox appeal he said "our judicial system has been subjected to a systematic denigration by a well-organised operation of a journalistic and political nature".
In April 2009, Preston appeared in a segment of 48 Hours on CBS, in which he argued that the case against Knox was "based on lies, superstition, and crazy conspiracy theories".
[54] On 4 December 2015, Mignini was disciplined by the High Council of the Judiciary for violation of correct procedure in the arrest of Sollecito in November 2007.
[56] In June 2010, Mignini was the prosecutor involved in the case of porn star Brigitta Bulgari who was arrested and held for 11 days after being charged with child pornography; this followed the surfacing of a mobile phone video showing 15-year-old boys touching her breasts while she performed as a stripper in an Umbria night club.