Whatever the issues with Mincione's original management of the secretariat's investments – and they are significant enough for Vatican News to label them a "conflict of interest" – the specific episode that seems to have led to Torzi's arrest did come after Becciu's departure from the department and after a decision, apparently taken by Peña Parra, to sever ties with Mincione.
If Vatican prosecutors choose to focus on what Becciu has called "a specific crime for which [Torzi] alone is responsible," the chances of a wider accounting of affairs at the secretariat may be slim.
On the other hand, those same prosecutors have, so far, played a much stronger hand than many expected at the outset.
A series raids by Vatican gendarmes, beginning in October last year, have reportedly had the personal, even explicit backing of Pope Francis.
Among those raided (and still of unconfirmed employment status) is Perlasca himself, suggesting the scope of enquiry extends beyond his own self-professed role of whistleblower against Torzi.
The raids also resulted in the (still unresolved) suspension of Fabrizio Tirabassi, a layman who worked overseeing the secretariat's investments under Perlasca and Becciu, and after their departure from the secretariat.
What conversations investigators have had – or have yet to have – with Tirabassi remain unclear. But it seems certain that some explanation will have to be given for how he ended up as a director of the holding company Torzi allegedly used to charge the Holy See for control of the London building. It seems at least possible, given the scope of the raids already carried out, that he would also be asked for a more complete account of his dealings with other business figures, like Mincione and Enrico Crasso, on the secretariat's behalf.
There are other indications that prosecutors are casting their net wider than a single transaction by Torzi.
Swiss authorities have reportedly confirmed that tens of millions of euros have been frozen in several bank accounts as part of the Vatican investigation. According to Corriere della Sera, at least some of these accounts were under the control of Mincione, Crasso, and Perlasca.
Perlasca has insisted that he has no personal accounts in Switzerland. He has also said that he "had no signature power" on secretariat accounts and that he "only had the power to sign in conjunction with another superior." "In other words: I could not move a single penny," Perlasca said.
This being the case, there would be an extensive paper trail of who authorized what transactions going back years, and it becomes difficult to see how final responsibility could be left with subordinates like Tirabassi, or to Perlasca himself.
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Similarly, if prosecutors are narrowly concerning themselves with Torzi's alleged crimes, there are not yet clearly stated reasons to freeze accounts linked to Mincione and Crasso.
Amid attempts to minimize the significance of Torzi's arrest, the signs are that investigators are pursuing far wider concerns about the secretariat's finances, concerns which may go higher than relatively obscure curial officials.
The questions for prosecutors will now become: how much latitude do they have to follow all the leads they have been given? And how much stomach is there in the Vatican to act on what they find?