Bloody Sunday should fill the British ruling class with shame. Instead, some of their spokespersons send up flurries of outrage to distract attention from the truth.

The two new TV dramas marking the 30th anniversary of the massacre have been denounced by a variety of commentators, some of whom haven’t felt it necessary to see the films before delivering their judgment. Rather in the way they initially approached Bloody Sunday itself.

The line of attack is that the films are one-sided, depicting the paras as murderers and all the dead and wounded as innocent victims. What’s more, it’s said, there’s an imbalance between the continuing concentration on Bloody Sunday and a relative lack of interest in other Northern atrocities, in some of which just as many died.

But what drew the writers of the films – Jimmy McGovern’s Channel 4 production Sunday and Paul Greengrass’s Bloody Sunday for ITV – were precisely the things which made Bloody Sunday different, and which gave the day a pivotal significance in the politics of Britain and Ireland.

When the paras killed 13 people in the Bogside because they’d stood up and demanded equality, many people, particularly young people in Catholic working-class communities across the North, saw themselves facing a choice between giving up the fight for equal rights, or getting armed and fighting back. Both films accurately depict the mushroom growth of the IRA beginning before the stench of cordite had cleared from Rossville Street.

The killings hadn’t come about by accident or misunderstanding or because psyched-up soldiers ran amok. The British Commander of Land Forces in the North, Robert Ford, in a memo dictated three weeks before the event, on January 7th, put his intentions on record: “I am coming to the conclusion that we must shoot selected ringleaders of the Bogside young hooligans.” Ford’s preferred action, and his role on the ground urging the paras to “Go on... go and get them”, is, again, portrayed accurately in both films.

Far from pre-judging the truth, these sequences are meticulously built around established fact.

Similarly, the films’ depiction of soldiers planting four nail bombs on the dead or dying Gerry Donaghy, 17, is not “bloody fantasy” (Daily Mail), but the only conclusion possible from a mass of evidence, including from two doctors who had examined the stricken youth, that there were no nail bombs in his pockets when the car in which he was being driven frantically to hospital was stopped by soldiers at a roadblock.

The depiction of Barney McGuigan inching out from cover waving a white handkerchief towards Paddy Doherty bleeding his last in the shadow of the Rossville Flats and crying, “I don’t want to die on my own”, and a para from across the street shooting him in the back of the skull, is exactly as scores watched it happen.

In fact, all the deaths in each film have been reconstructed from published evidence. Bloody Sunday didn’t happen on a lonely road or in the dead of night, but in bright winter sunshine in a built-up area, seen from the flats and houses all around or from behind walls and bits of street furniture where marchers had crouched for cover. The reason the issue has remained raw for 30 years is not that the basic facts are elusive but that they are obvious.

Hostility to the films doesn’t arise from concern for the truth but from an unreadiness to acknowledge the truth.

Both films depict the killings face-on and at close range. Nobody dies prettily.

Each has a para who watches the slaughter with dismay and is assailed by guilt afterwards. This is Soldier 027. The depiction is taken from his witness statement to the Saville Inquiry, which also helps provide the basis of scenes showing other paras filled with savage exultation.

The films look at the facts from different angles. Greengrass tells the story mainly through the eyes of SDLP MP Ivan Cooper (James Nesbitt). One problem with this device is that it requires that Cooper be shown at the heart of the action throughout and involved in every key decision on the civil rights side. He is depicted making his way to the march through reverential crowds, explaining to supplicants asking about television licences that, today, civil rights must take priority. These scenes, while they do not impact on the account of the killings, portray Bogside people inaccurately. They are far too full of deference. Bernadette Devlin, the most popular and infuential person in the Bogside on the day, is played as a shrill fool.

Greengrass also includes a scene in which a priest delivers a patronising lecture to Gerry Donaghy, which a docile Donaghy submissively accepts. As a depiction of the relationship between priests and Bogside teenagers in 1972, this is laughable.

Greengrass accepts the cock-up theory of Bloody Sunday. The massacre didn’t flow from deliberate strategy but from a combination of belligerent stupidity on the part of officers like Ford and confused aggression from brutal soldiers on the ground.

McGovern shows the source of the evil which burst on the Bogside located in the conscious intentions of the political, military and legal elite, whereas Greengrass suggests a general moral deficiency in the political and security apparatus.

Greengrass implicitly concludes that what the Bogside needed was trust in the leadership of decent men like Ivan Cooper. McGovern suggests that the answer lies somewhere in the sense of working-class oneness and sheer indomitability of the people themselves.

Greengrass’s depiction is undeniably powerful. More documentary than drama in style, it is simply structured, taking the events of the day in sequential order, building tension through intercuts between jaunty banter on the march and the grim business of the paras making ready. The violence is caught in jerky, hand-held sequences seemingly snatched on the run, zooming in on terror, swivelling away to project the images unmediated into the audience’s face. The scenes of Cooper distraught at Altnagelvin Hospital, beseiged by the pain all around him of families discovering that their son or father or brother is among the dead, will remain vivid in the memory long after the detail of dissection of the film has faded.

McGovern’s film is more deliberaterly structured, with a prelude sketching events as they build towards the Bogside march, and showing the Widgery Tribunal afterwards and the repercussions both at political level and in the shattered lives of families left behind. Throughout, he looks at the unfolding horror through the families’ eyes. The portraits are subtly coloured and precisely delineated. You get to know the Youngs the way you know people you call in on without knocking the door. Brid Brennan, as John Young’s mother, gives a ferociously understated, shattering performance. She forgives the soldier who has killed her son, “not for his sake, but for the sake of the sons I have left”.

Discussion of the differences between the films shouldn’t obscure what’s entirely positive and brilliantly realised about both, that they present Bloody Sunday as the pitiless murder spree which it was, carried out on behalf of a ruthless government by a kill-crazy regiment and covered up by a class-conscious liar, the Lord Chief Justice of England.

Bloody Sunday airs on TV3 and ITV on January 20th. Sunday airs on Channel 4 on January 28th