In this work I present an analysis of an iconic image from the period in Italy known as the “years of lead”: the photograph which shows a protester (Giuseppe Memeo) pointing a gun at the police in the middle of Via De Amicis, during a demonstration held in Milan in the afternoon of 14th May 1977. A few days later, Umberto Eco wrote an article for “l’Espresso” in which he maintained that the symbolic isolation of the protagonist would lead to the process of isolation of the members of P38 group (the violent fringe of the movement). Almost 35 years later, in 2011, Paolo Fabbri and Tiziana Migliore wrote an essay in which Eco’s interpretation is completely overturned. The two semioticians focus their attention on three other members of Autonomia Operaia who have a precise role to play in the scene and — together with Memeo — look like an “attack squad” (or, in semiotic termis, an actantial structure in action). Fabbri and Migliore believe that the lone Autonomia member is a semiotic construction, created by Eco for ideological reasons: in the view of the authors, Eco saw in that photo an individual hero, detached from the masses, his aim being to highlight the folly of the armed struggle and the isolation of the P38 group. In this article I try to demonstrate that Eco’s reading is a legitimate one and that the sense–effect of the photo is the isolation of the protagonist. I develop my theory through a closer semiotic analysis, enlarging the corpus and examining also some of the other photos taken that afternoon to see whether the effect of isolation is confirmed and — if it is — in what ways.[...]