I glimpsed the TV news report - a young man killed at Berga’s Patum firework festival - out of the corner of my eye as I dashed to the whistling kettle, and thought, “This was bound to happen; it was only a matter of time before crazy firework stunts claimed a life”. My presumption was wrong. Josep Maria Isanta had been stabbed to death with a street fighter’s butterfly knife.

Amongst those arrested were four Ecuadorians, two Dominicans, two Moroccans, two Poles and eight Spaniards - “ocho españoles”, according to the Catalan press, which has generally pointed out that one of the “españoles” was wearing a jersey supporting the Spanish national football team. Why has this seemingly innocent sporting detail so captivated the attention of our scribes?

Because they take their contrarian lead from Berga town hall, the police and Catalonia ’s home minister Montserrat Tura, who all claim that the riot has no political or xenophobic connotations. Yet the foreign make-up of the rioting group belies this, and the press’ use of “españoles” (rather than “catalanes” or “berguedanos”) implies - does it not? - that Spaniards who are not ethnic Catalans can be lumped together with the immigrants as disturbers of the peace. Especially when the victim is a noted local catalanista, killed in the middle of a nationalist concert.

Predictably, the conservative nationalist party Convergència I Unió (CiU) has chosen to capitalise on the tragedy: the district council (Consell Comarcal del Berguedà), controlled by CiU, has issued a statement supporting rowdy mass demonstrations outside the courthouse, egged on by the town’s former mayor Josep Maria Badia (CiU). Significantly, the communiqué was issued by the Youth Council (Consell de Joventut), headed by CiU politician Sergi Roca , mayor of the nearby town of Bagà . The demonstrations, according to CiU are “appropriate to the circumstances”. Circumstances which could be laid at the door of CiU, one might add.

CiU leader Artur Mas was so keen to politicise the event that he scored an own-goal by calling the Berga events “the start of kale borroka in Catalonia ,” in reference to Basque nationalist street fighting. Mas’ slip was jumped on by Raúl del Pozo, writing in El Mundo that “While [Catalan] politicians boil their brains revising statutes, the Moros y Cristianos of the Patum have been Catalanised”. Calling a spade by its name, kaleboel blog writer Trevor Ap Simon summarises the conflict as “fighting between Catalan fascists (sorry, libertarian bodies and left-wing separatists) and other scum”.

Boys will be boys, stabbing and bludgeoning each other on pretexts no weightier than a game of football. In Berga the celebration of ethnic identity, by its very nature dumbed down and simplistic, was the red rag to these bulls. According to the assailants’ girlfriends, the boys were boozed up and had snorted cocaine before the attacks, and were psyching themselves up to “bag ourselves a handful of hippies”. A strangely unbalanced antagonism, then: the victims on this occasion had their heads full of the martial bravado of Els segadors while their assailants resented them for being cliquey kumba brats with the keys to the town, free to party in the name of a nation to which xarnegos, sudacos and moros are emphatically not welcome.

In my opinion, the cool-headed Montserrat Tura is right to play down ethnic friction, though it clearly exists. By coincidence I was ten miles away on the day of the killing, to see the Corpus Cristi procession in the town of Solsona . Com Déu mana, the affair is properly Catholic and Catalan, and I wondered what the Arab boys of the town made of the swarthy-faced giant figures paraded through the streets, their folklore elements not quite forgotten; as one Patum web page says, “moros que tant mal record deixaren a Berga per generacions de generacions”.

Thousands of Berga townsfolk are now clamouring not only for justice, but that the elements involved in the attack (and their families, now refused service in the local supermarket) should be banned from the town - vigilante-speak reminiscent of Moros y Cristianos, and a wake-up call to law enforcers to apply the law to all. But ever since the Mossos d’Esquadra force was established, the Catalan police force has been under tacit pressure to favour their countrymen; one famous anecdote relates how, when the Mossos first took over traffic policing in Girona, a speeding Catalan driver complained about his fine by insisting that the Mossos shouldn’t be “persecuting one of their own”. This partisan sentiment can only have been strengthened by the Berga events. Indeed, the assailants’ defence lawyer, Ramón Cobas, had the outside of his Barcelona office defaced by graffiti and littered with flyers stating "Coba, abogado de asesinos. Catalunya no perdona".

Berga townsfolk complain that day-to-day policing by the Mossos has been lax, allowing petty crime to tyrannise the town; yet Guillem Bou, in Els millors dels nostres fills, his reflections on time spent as a curriculum designer at the Escola de Policia de Catalonia, writes that in Catalonia’s northern provinces, where the Mossos first took over the duties of a the Guardia Civil in 1999, it was customary for townsfolk to park illegally without fines in the central square because everybody knew whose the car was, and the owner could be fetched from a bar if necessary. “Massa presència i massa rigor en les normes” (too many police and too strict) was locals’ initial response to the Mossos, trained in metropolitan methods and regarded as quemacos (wide-eyed city types) by the backwoodsmen, who cold-shouldered Mossos efforts to either investigate crimes or forge friendships. Bou ends his chapter in dismay: “In these provinces, the future success of the force is in question. Any bright ideas?”

The indigenous people of Berga don’t want their own misdeeds looking into, yet they clamour for immigrants to be punished according to the letter of the law. The recent history of the Patum certainly paints this picture. The festival has always been a pretty drunken affair, and for several years the Patum has also seen vandalism and widespread drug taking amongst Berga’s youths. Last autumn the police staged a drugs swoop on a group of Catalan youths, some of whom were the target of the recent murderous attack. One suspects that the ill-feeling created by last year’s police action was in part to blame for Isanta’s death, as the Mossos were nowhere in sight during the festivities, turning a diplomatically blind eye to any excesses of revelling. So criticising the Mossos for arriving half an hour late to the scene seems unfair - especially as some reports suggest they had been given wrong directions.

Ethnic friction and confused policing priorities are part of the problem, but social degradation is the root cause of the strife. Berga, despite its beautiful landscape and proud medieval history, is a bit of a pit, its townsfolk close-packed in shoddy concrete apartments, and its youth unemployment high. The surrounding towns are worse. I know these places - godforsaken and Pujol-neglected strip-development warts like Navès, Puig-Reig and Espunyola, where textile mills, quarrying and logging have fallen into inertia and too many of the youngsters’ best chance of making a buck is to deal drugs, bringing them into conflict with immigrants who haven’t a hope in hell of becoming the town clerk.

And how about policing in Barcelona ? A thousand police officers are to swell the city forces for the tourist season. The bulk of the new agents are trainees, hardly the right type to take on hardened muggers. And the incumbent cops hardly set a good example. The nastiest thing I saw last week was a tourist, a well-dressed woman in her twenties, being ripped off on the Ramblas. She had been swayed by boho charm and tried her eye with the trilleros, the sleight of hand matchbox-shufflers who let you win a little until they win big. She suspected that she’d been cheated and was getting distressed. This was when she was threateningly manhandled away from the makeshift card table by the very thugs she’d assumed two minutes earlier were fellow punters. I recognise these men: some of them have been doing this for years on the Ramblas. The police know them too, but do nothing. And until the penal code makes bag snatching more than just a civil misdemeanour, conscientious cops will continue to be frustrated by the arrest-trial-release cycle.

While the tourist districts see more patrols, the poorer suburbs fester in a stew of Latino gangland intimidation. A recent schoolboy stabbing in Collblanc and its anti-Latino backlash have hit the headlines, but areas such as Hospital Militar, marked out with gang graffiti and frightening to go through on foot, stay out of the news for now, as nobody has died there yet. In contrast with Madrid, where 400 gang members have been identified and 50 arrests have been made this year, Barcelona’s authorities pretend the problem does not exist unless there is a killing outside of the gangs, such as the Ronnie Tapies murder in June last year, a case of mistaken identity in a gang initiation dare.

A musing on Spain’s ‘transition’ to democracy - once the low-level social control by police, priests and porteros had disappeared, why did nobody in government realise that well-organised social workers and probation officers would be needed? In God (and Cáritas) we trust…

Plain-clothed policing is the proven solution to many of the problems outlined above, in order both to keep a low profile amongst tourists and at festival time, and to catch hoodlums red handed. And if police laxity really is at issue, then plain-clothed supervision is also the answer: the method appears to be working for the highway police, judging by the squeals of complaint from traffic cops whose coffee-and-rum cocktails and puticlub sessions have been abruptly curtailed by surprise inspections.