The likelihood is that somebody killed him to keep him from disclosing information that would have been useful to the American people.
Carlo Tresca came to the United States in an immigrant ship forty years ago because he knew this was a country where he would be free to speak his mind against injustice. Living as a guerilla leader on the fringes of revolt among immigrant laborers against the exploitation they found here along with the opportunity, he very gradually became an American. Individual liberty, which the native born took for granted as they did the wealth and breadth of the continent, was his daily passion.
He edited a series of Italian papers- Le Plebe, Il Proletario, L'Avvenire, and finally Il Martello- in the romantic tradition of the revolt of the working class in nineteenth century Europe. In the first years his editorials were all for revolution. He was still drunk with the heady dream of an international working class that would bring peace and freedom to the world. As he took root here and became an American, defense of liberty in this country grew to be his dominant concern. The revolutions the nineteenth century agitators had dreamed of had come to pass and had brought instead of peace and liberty war and oppression to Europe and a new type of despotism more hideous than any in history. Inside the circle of the transplanted Italian world he moved in, Carlo Tresca struggled to keep the Fascist and Communist organizations that had made Europe a hell from reaching out into America. In Il Martello he used to the fullest the freedom of speech which is our greatest bulwark against the subversion of our liberties. Believing that the United States government was defending the freedom of all men against oppression in the war with the Axis Powers he did all he could to help the FBI discover and root out the agents of those foreign organizations that were at work among the foreign born in this country. It was surely as a fighter for American freedom that he was shot down.
The people of America who have made such sacrifices to win the war against murderous forces across the seas have the right to demand energy and courage in their officials at home in defense of that fabric of civilized society which is the protection of all of us.
The following pages contain a summary of what is now known and surmised about Carlo Tresca's killing. I don't know which one of the suggested clues is the correct one, or if any of them is the correct one, but it is clear that clues exist.
Possibly the discovery of the murderers will prove a difficult and thankless task. In the islands near Japan our soldiers have performed tasks vastly more difficult and thankless and a great deal more dangerous. If any public official has let himself be convinced that the interests which might be involved are too powerful to reach, or that this is merely a routine murder case to be written off on the debit side of his record, and that therefore the easiest course is to let it slide gently into oblivion, perhaps he will now think the matter over and remember how much is at stake and how little it will cost him to do his duty with energy and perseverance, compared with the total sacrifice we have demanded of the men of our fighting forces.
John Dos Passos