They are carried out by constantly studying the criminal phenomenon and analysing the activities of the subjects who are suspected of belonging to Mafia-type organizations. In particular, preventive investigations aim at outlining:
• structures of criminal groups;
• branches and links at national and international levels;
• targets and modus operandi ;
• any other mafia-type activity, including extortions.
This preventive activity is the starting point of investigations, which will then check “on the spot” the reliability and accuracy of the investigative hypotheses.
Within preventive investigations, interdiction measures play a major role in the analysis of the data collected and in supporting the subjects involved in the monitoring activity, above all the Prefects, who are the local authorities responsible for evaluating the info-investigative findings of the control bodies and issuing the anti-mafia documentation.
In order to deprive mafia-type groups of the profits generated by criminal activities, proposals for the application of personal and asset preventive measures are submitted to the competent courts – to order the possible seizure and subsequent confiscation of assets.

The core of the DIA investigations is mainly criminal targets rather than single crimes. The DIA does not usually intervene on the basis of a notitia criminis but after having analysed the criminal phenomenon as a whole and mafia-type associations. The DIA investigations aim at ascertaining:
• responsibilities;
• roles;
• criminal activities;
• offences
of each mafia member.
The investigations are concentrated on strategically selected targets, without wasting information and investigative efforts. The DIA closely works with the law enforcement offices and authorities, which provide any type of cooperation to the DIA investigating officers.

The Branch “International Relations with Investigative Purposes” promotes and develops any link – at information and operational level – with foreign bodies, which are specialized in the fight against organized crime. It cooperates with the main investigating authorities of the EU Countries and the law enforcement authorities of other continental areas (non-EU countries, America, Asia, Africa and Oceania).
The Branch participates in the main law enforcement multilateral forums dealing with the prevention and fight against transnational organized crime.