Scalzone was born in Terni, Umbria. In 1968 he came to know Franco Piperno, and on 1 March that year he took part in the clashes against Italian police at Valle Giulia. A few days later his vertebral column was seriously injured by a desk thrown from a window by neofascist students, mostly belonging to the Italian Social Movement, that were occupying the faculty of Law of the University La Sapienza in Rome. About the 1968 movement, he said: