Initially the Red Brigades were suspected, although they denied having anything to do with the attack, but eventually some youngsters from the area, including Giuseppe Gulotta, were arrested and convicted, and then absolved after more than 30 years.

A mechanic from Partinico, considered close to anarchist circles, Giuseppe Vesco, confessed to the massacre and accused the four youngsters, only to retract his testimony immediately afterwards: he was found mysteriously hanged in his jail cell some months afterwards, despite having only one hand.

[5][6][7] Mandalà died of natural causes after years of jail in 1998, whereas Santangelo (until 1995, when he was arrested) and Ferrantelli, from an appeal to the next, fled Italy to Brazil and obtained the status of refugees there.

Gulotta, Santangelo and Ferrantelli obtained a new trial following the revelations of a former Carabinieri officer, Renato Olino, on the illegal methods used to coerce the four into giving false confessions.

Peppino Impastato, an activist and journalist who was later killed by the Mafia in 1978, did a series of investigations into the strange aspects surrounding the arrest and trial of Gulotta and his friends.

[9] Walter Veltroni, member of the Commissione Parliamentare Antimafia, stated that the perpetrators of the Alcamo Marina massacre were agents of the Gladio organization.

[9] According to him, the day before the massacre Falcetta and Apuzzo had stopped a van carrying weapons driven by men of the organization, who then assaulted the barracks in order to get them back.

[9] Following the declarations given by the former brigadier Renato Olino to a trapanese newspaper, according to which the confessions by Giuseppe Vesco and the others arrested were obtained through torture, in 2008 the tribunal of Trapani opened two inquiries.