Everyone, I suppose, knows what happened. In the early hours of Valentine's Day, Oscar Pistorius, Olympic gold medallist, double amputee and a national hero, fired four shots through a locked bathroom door and killed the woman concealed behind it. Pistorius claims he thought he was shooting an intruder, but the police have charged him with the premeditated murder of his girlfriend, the model Reeva Steenkamp.

The case dominated news around the world. A Canadian broadcaster called it the biggest story from South Africa since the release of Nelson Mandela. Which may say something about excitement levels in Canada, but not a lot about how these things play out in South Africa. Because the oddest thing about the Pistorius shooting is that it isn't really odd at all. Upwards of 15,000 times a year – and I am talking of a good year – a man reaches for a weapon, and someone, often a woman, will die. The country shakes its collective head, shrugs and moves on. When homicide is this prevalent, the story of a legless man who shoots his girlfriend may earn, at best, a paragraph in the papers because it has a piquancy that run-of-the-mill shootings tend to lack.

Yet the Pistorius shooting electrified the country. Perhaps because celebrity always trumps tragedy. The man who shot the model was famous for being the fastest runner in the world, "on no legs". He was an inspiration to other disabled athletes. Big sponsorship from the sports companies had made him a wealthy man.

But I think the reason why the Pistorius case obsesses South Africans is because it is so embarrassing. In the Valentine's Day fusillade the quintessential South African way of doing things is mercilessly revealed: it is a violent way, founded on machismo, carried out with gusto and it ends in bloodshed. It is a way that began long ago, in a country where the three Rs seldom meant reading, writing and arithmetic – but something closer to rugby, rape and revolution. It is such a cause of anguish here in South Africa because it is the way things are done.

What strikes the newcomer to South Africa is the ubiquity of violence; just beneath the surface of life run rivers of rage. This may be so because, ever since settlers arrived and shot the first local people they met as a way of signalling their future intentions, all contacts have been conflicts. It may be that, after years of enforced racial separation, people have no idea how to reach across the divide. But it is also, I sometimes think, because people actually like it this way. Violence is stitched into life and into language. Pistorius's website gets to the heart of it. Until recently we saw, together with the injunction from Nike to "Just Do It", the athlete in his green Lycra bodysuit bursting off the starting blocks, under the line: "I am the bullet in the chamber."

There was an enlightening moment during the Pistorius bail hearings, when the prosecutor asked why, if Pistorius was not a violent man, he had threated to break the legs of a rival in love. His defending counsel waved this away as nothing more than the sort of talk young people enjoyed. He is right of course. To read the sports columns is to find a celebration of roughing people up, knocking them dead and giving opponents a good "klap". The Afrikaans word may be translated as "a blow" but this does scant justice to its percussive power. The term can cover anything from a "love pat", to a mild slap, to a murderous beating, to a barrage of gunshots.

Much of the past four centuries of South African turmoil is summed up in this word. The question is who gets to do it, and to whom. It is the manly way of dealing with disobedience, disrespect or dissent: anything less violent is for women and wimps. Africa, in the posturing braggadocio of tough-talkers, is "not for sissies". The Pistorius case has raised the glimmer of an uncomfortable question: isn't it about time we sent for more sissies?

Many housing communities in South Africa now have private security stationed outside. Photograph: Eden Breitz / Alamy/Alamy

I grew up in Pretoria, as did Pistorius, and my home was in the eastern suburbs, close to what is now the luxury gated estate where Pistorius lived and where Steenkamp died. I went to school a bike ride away from what is now the Silver Woods Country Estate, where the shooting took place. Names are misleading in South Africa because in Silver Woods there was no wood and certainly no silver. There was only a stretch of bare, stony veld, now buried under a sprawl of expensive security estates, golf courses and shopping malls.

I remember it as a prime site for fights between boys, a place to settle scores, out of sight of parents or teachers. It also served as a battlefield where rival gangs clashed over girls and territory. The weapons were fists, or stones, and sometimes we used catapults. How no one was badly hurt is a mystery. But that was how things were done, prized and celebrated.

Our local "copshop" was the Brooklyn police station, where Pistorius was held throughout his bail hearing. Thinking back to those turf wars, where Pistorius's house now stands, I don't imagine the cops of my childhood would have done anything more than look on with fond recognition as we kids knocked hell out of each other. After all, that was what boys did.

The Silver Woods Country Estate is the kind of suburban fortress, increasingly popular all over the country. Most people know that it is poor South Africans, many of them black, who suffer most from violent crime. But there is a widespread and well-founded fear of attack among the middle classes of every race, and these formidable clustered villages seek to address that fear. They are the property market's response to the murder rate. Silver Woods is particularly proud of its solid electrified wall. There will also be other sophisticated measures to keep intruders out: closed-circuit cameras, electronic beams, sensors buried beneath the surrounding wall, guards on the gates and armed-response teams ready to race to the rescue when a householder hits the panic button.

Despite all these security measures, most householders probably also own guns. Pistorius used a 9mm Parabellum pistol when he shot Steenkamp; it was the only gun for which he held a licence but, as it turned out, he kept an arsenal of other weapons for which he had applied, but not yet been granted, firearm licences. He owned two revolvers (a Smith and Wesson 500 and a S&W .38-caliber) a powerful hunting rifle (a Vektor .223) and three shotguns (a Mossburg, a Maverick and a Winchester). When this armoury was carted away by the police, withdrawal symptoms were swift, it seems, since a reapplication for licences for these guns was lodged just days after the shooting.

When strict-sounding regulations limiting guns are voted into law everybody feels good about it. But the truth is this: guns are us. Guns in the bedroom, guns in the glove compartment and guns on the brain.

About a month ago, Pistorius took his girlfriend into a crowded restaurant and at some point during the meal he fired a shot. Happily, the bullet narrowly missed someone at the same table, and a friend loyally took the blame for the shooting. None of the diners reported the incident and the restaurant owner hushed it up because Pistorius and Steenkamp were regular customers. I see his point. You don't want your famous clients moving their custom to a more accommodating eatery.

When Pistorius pictured himself as "the bullet in the chamber", he was being unusually modest. Pistorius wasn't just the bullet in the chamber, he was also the bullet that whizzed passed his fellow diners; and he was the four bullets in the bathroom door where his girlfriend was hidden.

In South Africa, an estimated six million firearms are in private hands – one for every dozen people. Photograph: Nearby / Alamy/Alamy

How many guns are there in South Africa? Six million, say some – a dozen firearms for every 100 people. These figures, like the statistics on murder and rape, are unreliable. Much had been made of how very hard it is to get a firearm licence. The laws are strict, but there is little to suggest that anyone takes much notice of them. As long as guns confer power, prestige and protection, people are going to get their hands on them.

There are those who want only the police to carry guns. It's a fine idea, but it seems to take little notice of how things are. South African police officers are frequently murdered for their weapons; and in other ways the idea is downright scary. In the massacre of miners at the Marikana mine last year, the police used their weapons in a way that reminded everyone of the bad old days of Sharpeville. If that were not enough, Pistorius's bail hearing veered from tragedy into farce when the investigating officer who had charged Pistorius was himself charged with attempted murder for reportedly trying to shoot a taxi driver.

Not everyone who sets out to kill needs a gun. It is tragic that the Pistorius shooting has pushed out of sight a recent murder so brutal it shocked even South Africans. Seventeen–year-old Anene Booysen was gang-raped and murdered in a little town in the Cape by a group of men who knew her well. Her bones were broken and she was disembowelled. They used no guns because guns cost money and the desolate back lots of Bredasdorp, where Booysen was killed, are home to people who struggle to afford food.

If you look past the heap of weapons Pistorius kept in his home, you get glimpses of the impulses that feed the culture of violence, make it so powerful and so matter-of-fact. There are guns as a good night out, which Pistorius demonstrated when he went to dinner and indulged in a bit of gunplay between the starter and the sweet. There is gunfire as therapy. When asked by an American visitor if he often went to the shooting range at night, Pistorius replied that he only did it when he had trouble sleeping. Then there is the even odder idea that guns promote good causes, and that firearms, graphically displayed, make attractive fundraisers.

Just days after the murder of Booysen, and shortly before the shooting of Steenkamp, students at the University of Cape Town hit the streets to sell copies of their annual fundraising magazine. The full-colour cover showed a massacre reminiscent of the shootings at Columbine, but done South African-style. Beneath the familiar outline of Table Mountain, a batch of blood-stained corpses lie at the feet of two shooters, one of whom aims a pistol, the other wields an axe. The (male) editor of the magazine clearly thought it was fun, and admirers called it really "edgy". No one was terribly fussed: after all, this is South Africa. But I did ask myself where, when depictions of murder lose their edge, do you go next? Then it came to me: perhaps next year's student rag mag will offer a commemorative rape cover – that would knock the punters dead.

Exactly 50 years ago, I remember that the Brooklyn police station endured a surge of notoriety only matched when Pistorious was locked up in one of its holding cells. A Sergeant Arlow and his sidekick, Constable Hattingh, shot dead, without reason or warning, a black man they had arrested. Both escaped a charge of premeditated murder but were found guilty of "unlawful killing". Arlow and Hattingh were given suspended sentences and hailed as heroes by government ministers, and by much of white Pretoria. A remark of Arlow's has always stuck in my mind: "I only speak to a native once, and then I shoot." Arlow was another who saw himself as the bullet in the chamber.

Pistorius succeeded in his application for bail. This came as a disappointment to some – not least the ANC Women's League, which picketed the bail hearings, carrying banners demanding that Pistorius "rot" in jail. This is the same group that honours president Jacob Zuma for his tender regard for women – keeping their eyes averted from his past.

A few years back, the man who was to become the president was tried for, and later acquitted of, the rape of a family friend. Zuma's supporters outside the courtroom carried placards, aimed at the woman who had brought the charge. These read: "Burn the Bitch." Julius Malema, now a fierce critic of Zuma but at that time still a loyal supporter, threatened "to take up arms and kill for Zuma". When I consider the president's love of the ANC "struggle song" Bring Me My Machine Gun, which he still sings to cheering supporters, it takes me right back to where I started.

The terms of Oscar Pistorius's bail are stringent: he is to report to Brooklyn police station twice a week and he is forbidden to communicate with potential witnesses. Given the casual way young South Africans threaten to break each other's legs, this is probably just as well. In the period until his trial, set for June, he is not allowed to return to the compound where Steenkamp died

But the house will be looked after. Such is the murder rate that small industries have sprung up to tidy away the grim reminders. Reports suggest that two sisters, who work for Crime Scene Clean-Up, are likely to get the job. Known as "the blood sisters", they will scrub away the signs of the Valentine's Day shooting. It is specialised work, requiring more than the usual household detergents. The sister's website suggests they have much first-hand experience. Any evidence that may turn up, such as the spent bullet in the toilet bowl that the police failed to discover when they examined the crime scene, will be turned over to the authorities.

And that's how it goes in South Africa: another day, another visit from the blood sisters.

• This article was amended on 6 March 2013. The original said, in relation to an incident when a gun was fired in a restaurant, that Pistorius had taken the gun there. The person who narrowly avoided being hit by the bullet has said the gun did not belong to Pistorius so that reference has been deleted.