Mango decides to call his officer, Lieutenant Tagliari, who also leaves accompanied by the brigadier Antonio Ferraro and the carabiniere Donato Poveromo and arrive on the spot with a second gazelle at 23:05, then joined by a third patrol from Gorizia.

[3] The carabinieri Antonio Ferraro, Donato Poveromo and Franco Dongiovanni attempted to open the hood of the vehicle, causing the car to explode and being killed, while two others were seriously injured.

Colonel Dino Mingarelli, the old right-hand man of the general Giovanni de Lorenzo, was placed to direct the investigation on the matter.

Mingarelli immediately directed his investigation into the Lotta Continua circles of Trento, but the investigations did not obtain the expected results: the Milanese judiciary received information according to which the attack would be carried out by a group neo-fascist terrorist, which also included Ivano Boccaccio, a militant killed in an attempted hijacking of a plane at Ronchi dei Legionari airport in the following October.

The information had been given by Giovanni Ventura, meanwhile arrested for the Piazza Fontana bombing: the colonel however discarded the Milanese indication, as an order from the SID invited him to suspend investigations into the far-right terrorist group.