The turning point in the investigations a few hours after the solemn funerals of Antoninus, Mark and Matthew in the cathedral of Saints Peter and Mark of Alexandria, in the presence among others of the premier Giuseppe Conte, of the president of the Chamber Roberto Fico and of the Interior Minister Luciana Lamorgese . "You have to catch them, you have to do everything to catch them", was the appeal that the relatives of the three victims turned to the President of the Council. "We need to understand why and who did this", is the pressing invitation of the provincial fire brigade commander, Roberto Marchioni, to express the "rage" of the firemen in the face of this tragedy. The investigations led in a few days to a first result thanks to the "tight and articulated" activities of the carabinieri, under the orders of Colonel Michele Angelo Lorusso. Numerous technical investigations and interrogations, including in the last hours that of Giovanni Vincenti, owner of the destroyed building.
The man, whom the investigators had already heard more than once, responded to the investigators' new questions for several hours. "I have no information to give, the investigators are investigating," says Vincenti's son, Stefano, contacted by telephone. In the barracks also a lawyer, Laura Mazzolini of the Alessandria bar, and two women, who arrive and leave by car in about twenty minutes. "I witnessed the interrogation, I can't say anything," he merely declared the lawyer leaving the offices of the Weapon in Piazza Vittorio Veneto just before 2 am. "I think that soon – he added – you will have official statements". Shortly afterwards the prosecutor Cieri also left the barracks, limiting himself to a "no" with his hand turned to the journalists by the car.
Also in front of the provincial command were some citizens who, having heard of the interrogation, reached the offices of the weapon. The news of the judicial police detention arrives at 2.29 with a ten-line statement that refers to the details of the operation. Shortly afterwards, Vincenti also left the barracks with two other people aboard a gray Alfa Romeo Giulietta. No one knows where he was going.