But the weapon Simone chose to take with him on the trip to Genoa was one made for concealment: a butterfly knife with a thin 11- centimetre blade folding neatly away inside the two hinged halves of its wooden handle.
Simone, a 19-year-old apprentice gardener, and Matteo, a year younger, had known each other at school in Lorentaggio, a working-class quarter of Milan near the San Siro stadium. Both were members of the self-styled Gruppo Barbour, a dozen fans of AC Milan whose membership fee was the price of a Barbour "Bedale" waxed jacket imported from England: 320,000 lire (£130), as much as Simone earned in a week-and-a-half.
In a panic last Sunday afternoon, a few hours after Matteo had lent him the butterfly knife, Simone was pulling off his dark blue Barbour and swapping clothes with another member of the group. The knife was hastily hidden in a wine carton. Then they entered the stadium with the rest of the crowd, hoping to blend in. Later, after the match had been abandoned at half-time, they were held behind and, along with hundreds of Milan fans, had their photographs taken by the police before being released.
Simone got back to Milan that night, but just after dawn on Monday the police arrived at his mother's apartment to arrest her son on suspicion of murder.
They drove him back to Genoa and took him to San Giuliano police station. There, and later in his cell at Chiavari jail, he underwent a series of interrogations that were swiftly leaked to the newspapers.
Simone apparently needed little encouragement to make a full confession. "I did it in self-defence," he said. "I was frightened."
In the presence of his lawyer, he told an examining magistrate how he and his friends had been confronted by a group of Genoa supporters outside the Stadio Communale Luigi Ferraris. How the two groups had converged. How some of the locals seemed to make threatening gestures. How he panicked and took out the knife. How one boy ran towards him. How the boy fell. How he saw blood on the ground and on his blade.
How he hadn't meant it.
WHEN they buried Vincenzo Claudio Spagnolo in Genoa on Thursday morning, more than 10,000 people turned up outside the church of San Teodoro, a short walk away from where he had lived.
Spagnolo - Claudio to his family, Spagna to his friends - was a perfectly ordinary 24-year-old who had finished his compulsory military service and was looking for a job. Now his image is all over Genoa, on a fly-poster produced by a group of his friends. Besides a message of farewell, it bears an enlarged snapshot of Spagna, posing on a chromed Vespa in jeans, baseball boots and polo shirt, with his sunglasses pushed up on to his cropped head, looking like an extra from The Bicycle Thieves.
"It's not possible for a young man to die like this for a game of football." The grief-stricken words of Cosimo Spagnolo, the dead man's father, were repeated from the pulpit by Cardinal Giovanni Canestri. "But enough of words," Canestri continued. "Silence! And let those words and that silence quicken our consciences. Stop, reflect and pray. To die like this for a game of football . . ."
In the congregation, listening to his address, was David Platt, the captain of England, present as a member of the Sampdoria squad, which shares the Ferraris stadium with Genoa. Today, like every other sportsman and woman in Italy, Platt is having the day off, a result of the decision taken on Monday by Mario Pescante, president of the Italian Olympic committee, which acts as an umbrella for all the nation's sports organisations, amateur and professional.
A day of silence. A day on which, throughout Italy, no sport will be played. No football. No basketball. No rugby. No hockey, on grass or ice. No indoor athletics or cross country. No swimming or cycle racing or nordic skiing or rifle shooting. Only a Davis Cup tie in Naples against the Czech Republic has survived: the suspension, it is felt, is a domestic matter, and there is no good reason to inconvenience guests from abroad. Otherwise, from the Olimpico in Rome to the humblest village pitch in remoteCalabria, nothing will move.
In a poll conducted early in the week, four out of five Italians approved of the stoppage: an astonishing degree of support in a country whose insatiable appetite for sport is fed by three daily papers.
But not everyone agrees, and some of the dissenting voices were powerful ones. The president of the Italian football federation, Antonio Matarrese, heard about the tragedy when he returned from a Uefa meeting in Switzerland. Invited to make an immediate response, he said he believed that the decision to abandon the Genoa-Milan match had handed a victory to the hooligans, and that further disruption of the sporting calendar would deepen the impression that sport could be controlled by thugs. The following day, after receiving severe criticism in some of the papers, he was talked round by Pescante.
The dissidents included Gianni Rivera, Milan's former "golden boy", who described it as "a decision taken with the heart rather than the head - it isn't a solution". Oscar Washington Tabarez, the coach of Cagliari, said: "It's not fair to punish everybody." Zdenek Zeman, Lazio's coach, observed: "It won't change anything."
But David Platt's balanced view seemed to represent the majority of professionals. "I think the cancellation was a foregone conclusion," he said at Sampdoria's training ground on Thursday, a couple of hours after attending the funeral alongside Ruud Gullit, Roberto Mancini, and the rest of his team-mates. "It's to show that the matter is being taken seriously. What it actually does apart from that, I'm not too sure. I don't think that by itself it's going to stop hooliganism in Italy. I ask myself, are the people who cause the trouble really football fans, or would they be up to something similar if there wasn't any football? But the underlying feeling is that, yes, it's right to postpone the games because it sends a message that we don't support this kind of thing. And that there is something bigger than football."
The murder of one man in Genoa is producing the kind of convulsive reaction in Italy that England experienced in the aftermath of 41 deaths in the Heysel stadium and 95 at Hillsborough. Suddenly, something must be done. The Pope issues a message to the young people of Italy, warning against an excessive fondness for football and discotheques.The new prime minister, Lamberto Dini, says that if football doesn't reform itself, he'll do it.
Identifying the most effective measures is the problem, although most commentators seem to believe that Italy should profit from the work done to counter hooliganism in England. But few agree on the details. David Platt believes that putting cameras in the stadiums would help the police to spot trouble quickly: "But, of course, last Sunday's murder happened outside the stadium," he added, "so it wouldn't have prevented that."
Milan's Gazzetta dello Sport, which has campaigned hard on behalf of the suspension (against its chief rival, the Rome-based Corriere dello Sport), advocates the disbanding of the "ultras", the hard-core fans who traditionally benefit from free tickets and subsidised travel to away matches. Platt, who is in his fourth season in Italy, is not sure about this. Most "ultra" groups, he pointed out, are genuine supporters' associations. The leader of Sampdoria's ultras, he said, has the ear of the club president, giving the fans a say in how things are run.
"There's a real warmth and togetherness between the players and the fans here," he said. "And there's a much bigger following for sport in Italy than in England. You see far more women and children in the stadiums. It's an intense game here, but this is not a violent society."
THEY BURIED Spagna on a cold morning, under grey skies. Now the scores of wreaths that accompanied his cortege lie where he fell, on the western side of the stadium, beneath railings covered in scarves and flags and handwritten messages left by those whomourn.
He died a few yards from a street sign that reads: "Via James Richardson Spensley / Medico- Educatore / Fondatore del Genoa Cricket and Football Club". The red and blue colours of the club Dr Spensley founded in 1884 predominate in the display, but they are joined by others: from their neighbours Sampdoria, from Juventus, Roma, Parma and Cagliari. And from elsewhere: Barcelona, Anderlecht, Liverpool.
On the third day of his incarceration, Simone Barbaglia wrote a letter to his victim from his prison cell.
"To Vincenzo," it began. "We shared a mistaken passion for football. Because of that, maybe you can understand me. I didn't want to do it! I didn't want to do it! Now I'm here, alone, with my desperation and the pain of what I've done. I look for courageto face the punishment. Forgive me for something only you can understand. Simone."
On this silent Sunday, an entire nation is trying to understand, and hoping to learn.