Our national legal system, through the Anti-Mafia Code, devotes great attention to the fight against mafia infiltration in the economic and social sectors, not only when it pollutes the economy but also, as stressed by the jurisprudence, when it influences both business between private and state entities and between private entities.
The legal system provides for a sort of social protection – like an early prevention mechanism – entrusting the  Prefects  with the power to issue the Anti-mafia documents, upon request of the public administration. These documents are issued after a careful analysis of the evidence highlighting mafia infiltration. The Law  provides for some of these documents while others are not specified but rather envisaged by the jurisprudence. At the end of this preliminary activity, a certificate is issued in the form of  communication or  information note, authorizing or banning the participation in a tender or public contract.
The Direzione Investigativa Antimafia has always paid great attention to the prevention and fight against the attempts of mafia infiltration in public procurements, being a driving force in supporting Prefects with the above-mentioned antimafia documentation.
Indeed, tenders are one of the strategic interests of mafia organized groups, allowing them to reinvest huge economic resources and to benefit from future earnings.
To this end, the DIA headquarters hosts the Public Procurement Observatory, which, by law,  is one of the institutional parties the Prefects have to inform when taking antimafia interdiction measures.
The Observatory has an important database containing all relevant data and information and ensures circulation of information with local offices, in particular with the officers and officials of the Interagency Groups at each Prefecture.
In 2015 when the  EXPO was held, the Direzione Investigativa Antimafia was one of the core agencies involved, within the national mechanism for combating mafia infiltration in public procurements. It ensured  at central level,  the monitoring activity falling under the jurisdiction of the Ministry of the Interior and, at local level, the participation of the Interagency Group at the Prefecture in Milan.
Antimafia preventive investigations concerned both tenders for the so-called “Grandi Opere” (infrastructures and priorities to support the country development), as defined by the Law on Objectives, and other public tenders. They consisted in monitoring multiple companies and accessing building sites to check mafia infiltration attempts.
In order to prevent and fight attempts of mafia infiltration, the procedures regulating the monitoring of Grandi Opere  primarily  consist in undersigning protocols of legitimacy, with binding effect, between contracting authorities, developers, and the prefectures- local Government authorities having the jurisdiction. This antimafia monitoring, including preventive monitoring, covers all phases of the works and the entities involved.
The need to widen and strengthen the measures aimed at preventing and combating mafia infiltration in public procurements has led to agreements, such as protocols of understanding, which over the years have  upgraded the security in this field.