© Unknown.An account by BBC investigative journalist John Ware on what he learned about “Britain’s secret terror force”, the Military Reaction Force.
10 pm, May 7 1972, Belfast: a 16-year-old youth emerges from a school disco with his girlfriend. Like many other youths in this part of Catholic, nationalist west Belfast, he had previously thrown stones at the British army.

Suddenly there is a burst of machine gun fire from a car. As it speeds off, the boy writhes in agony from bullets in the stomach and arm.

A few weeks later a car cruises into view of a bus stop. The driver is said to have waved a friendly wave, only for a machine gun to flame into life from a rear window, cutting down three men chatting to each other.

Between May and September 1972 -- the most violent year of the conflict -- there were several similar 'drive by' attacks, which nationalists assumed were by loyalist gunmen.

In fact the gunmen were soldiers in civilian cars, dressed up as locals, and sometimes armed like the local IRA -- with the IRA's favourite weapon, the 'Chicago grinder', a Thompson sub-machine gun also favoured by the 1920s gangster al Capone.

In each case the soldiers claimed they were fired on. Yet there was no independent evidence to show that any of the dead or wounded were armed, or that they provoked the attacks, or even that they were members of the IRA.

These soldiers belonged to an experimental undercover British army unit called the Military Reaction Force (MRF) whose mysterious activities have been the subject of lurid speculation in Belfast for 40 years.

Ex-MRF members have generally shunned the limelight. So controversial were their activities that the force was soon disbanded.

The closest former MRF soldiers have come to breaking cover is as the pseudonymous authors of two semi-fictionalised paperbacks, one of whom has referred to the MRF as a "legalised death squad".

The factual account of the MRF may not be quite as colourful. Nonetheless, the evidence gleaned from seven former members, declassified files and witnesses does point to a central truth: that MRF tactics did sometimes mirror the IRA's.

Co-located with the Parachute Regiment in Palace Barracks just outside Belfast, the MRF was shielded even from the view of their uniformed comrades by corrugated sheeting.

Within the MRF compound were prefabricated units housing an operations and briefing room, an armoury and space for cars, typically Hillmans and Ford Cortinas with microphones built into their sun visors. Some were stolen. MRF members were selected from all regiments, including the SAS and Special Boat Service. They had to be single, and able to work unsupervised using their own initiative.

Their main role was surveillance by melting into the background of nationalist west Belfast. To help them live this role, members were 'demilitarised' on joining. First names were used instead of ranks.

These soldiers did not lack for cold courage. By adopting a variety of disguises -- drunks, road sweepers, dockers and press photographers with fake press cards -- they ventured into IRA strongholds.

Soldier E recounted how he posed as a merchant seaman in Ardoyne, a near suicidal act of courage in this IRA lion's den.

Had he been banged up against a wall and his underarm Walther pistol discovered, torture and execution would have followed. "It was a hairy job and we used to get the shakes after it, but it had to be done," he said.

The soldiers we spoke to also said the MRF had a "hard-hitting anti-terrorist" role. "We were not there to act like an army unit," explained Soldier F. "We were there to act like a terror group."

One tactic was to deliberately act as bait, to entice the IRA to come out to fight. "It was like dangling a red flag to a bull," said Soldier E, "to get them to engage you rather than their covert operations, laying ambushes and bombs etc."

The bait -- typically -- was an unmarked vehicle with two soldiers in the front armed with pistols, and a third in the back seat with a sub-machine gun.

"You'd have one [car] standing off and we'd put one as a decoy in such a place as they would come up to you," explained Soldier G. And if they did? "If they had weapons on them they were f***ing going down. That's the beginning and end of it."

These baiting tactics were outside the rules governing the use of lethal force known as the Yellow Card, which required a soldier to challenge a gunman, offering him the chance to put down his weapon before opening fire -- unless the soldier felt his life was in imminent danger.

In the real world of Belfast 1972, one man with a gun confronted by another was only ever going to end one way. All of the MRF soldiers we spoke to say they often ignored the Yellow Card. "If we didn't do what we did, nothing was going to get done," said soldier H, a grizzled SaS veteran.

And in 1972, according to Anthony Le Tissiet, then a major in the Royal military police, the prevailing attitude was that "you could just about do anything you wanted".

In this piratical climate, releasing a few enthusiasts on to the street and spontaneous events were bound to occur.

"It was a time when we enjoyed the challenge of going out and having a fight," said Soldier H.

"We had to break the rules in many cases but not so badly that, you know, there was murder done, or anything like that," said Soldier G.

That depends how "murder" is defined, and for Soldier G shooting someone found with a weapon in a car -- even if it wasn't actually on him -- doesn't seem to have qualified: "The rule of thumb was to take him in and get some information out of him, but we were sick of that sh*t, you know."

What about "assassination" in its conventional meaning: a cold-blooded plan to identify, track down and execute a target?

None of the MRF soldiers we spoke to say that they were given instructions to hunt down a named member of the IRA for execution.

On the other hand, the MRF had an effective way of identifying known players. Attached to the MRF was the British army's first agent-running unit in Northern Ireland where captured members of the IRA were turned.

Known as 'Freds', they were housed in married quarters on the base. They were taken out in armoured personnel carriers, and through its slit windows they identified members of the IRA who were then photographed. MRF patrols were sometimes tasked on the basis of intelligence provided by the Freds.

Was there within the MRF, an understanding as to what would be permissible if some of these more active IRA players were spotted in circumstances where they could be dispatched?

Soldier D sometimes patrolled with a silenced weapon. "We had to use our own initiative," he said. "That's why I was selected for this operation -- to use my own initiative."

If he came across a "well-known shooter" who'd carried out assassinations and if the opportunity arose, he would be "taken out".

By the start of 1972, according to the army, soldiers were "killing or wounding about 15 terrorists a week".

It's impossible to say whether the MRF's contribution to that was disproportionately high in relation to its size of about 40 men.

Many MRF soldiers are now dead, there were daily multiple shootings of unknown origin and the MRF's day-to-day records have been destroyed.

However, some MRF soldiers do seem to have taken a trigger-happy approach to vigilantes manning barricades -- often amateurish affairs erected to protect nationalist enclaves from attacks by marauding loyalists.

As potent symbols of insurrection, it fell to the army to discourage their presence.

Soldier G admitted he and other MRF soldiers engaged in a "fair bit of" drive-by shootings -- provided he saw a weapon. "You just ease up, slow -- and spray a few."

Some soldiers said they operated on the assumption that there would always be a weapon at a barricade --whether it could be seen or not.

"We'd give 'em a blast anyway," said Soldier F, with the insouciance of someone blow-drying his hair.

On the night of May 12 1972, an MRF patrol gave a few blasts of automatic and pistol fire to half a dozen men dismantling a barricade close to a loyalist area in south Belfast.

Patrick McVeigh, a father of six children, died on the spot.

The MRF soldiers told the Royal Military Police they'd been confronted by up to half a dozen gunmen who opened fire.

Yet forensic tests on McVeigh and his friends were negative, nor were any of them in the IRA.

A uniformed soldier quickly on the scene said: "We were under the impression we were dealing with ordinary guys trying to prevent trouble who weren't gunmen."

Covering up the MRF's role, an army statement said the attack was a "motiveless crime" -- code for loyalist murder gang.

Ten minutes earlier, the same MRF patrol car that had killed McVeigh had been in convoy with another MRF patrol car which had also opened fire on another barricade, wounding 19-year-old Eugene Devlin who was walking close by.

Devlin was not a member of the IRA and he too tested negative for firearms. Again the MRF soldiers told the military police they came under fire. Devlin insists the only gunfire came from the MRF car.

"We operated initially with them thinking that we were the UVF," said Soldier H. But to what end? "We wanted to cause confusion," said Soldier F.

"My take on that was 'Great, no problem'," said Soldier H, who was "quite happy" for the IRA to think the UVF was responsible.

Did some MRF soldiers also seek to exacerbate the murderous internal tensions amongst republicans by mimicking the Official IRA from whom the Provisional IRA had split in December 1969?

Stored in the MRF's own armoury were two Thompson sub-machine guns, then a weapon popular with both IRA factions.

One of the two Tommy guns was privately owned by Captain Hamish McGregor, one of the MRF's commanders, who had won a Military Cross in Aden.

The other had been captured from the IRA by the police and then loaned with ammunition to the MRF by the Special Branch. The MRF had told the Branch that they needed the guns for training to familiarise their soldiers with the sound and characteristics of a standard enemy weapon.

However, the Tommy guns appear to have had another use as well.

We found a major who had told the Royal Military Police that, when patrolling his area, one of Captain McGregor's section leaders had sometimes been armed with a Thompson.

His name was Sgt Williams, a Royal Military Policeman on attachment to the MRF and he had also been the commander of the MRF patrol that shot dead Patrick McVeigh.

Soldier H told us that he too sometimes took out a Thompson on patrol because it had "hitting power and it felt better... it had a bloody big slug".

Shortly after noon on June 22 1972 a volley of "bloody big slugs" from a Thompson hit three young men standing at a bus terminus on the Glen Road, west Belfast, and a fourth man whose bedroom was in the line of fire.

According to one witness, a car slowed to a halt 20 yards away on the main road and the driver gave a friendly wave -- only for the black barrel of a Tommy gun to flame into life from the back seat.

Once again, the gunman was Sergeant Williams.

Soon word reached detectives that a plain-clothes army unit was operating in west Belfast with its own rules.

"I thought there was some great master plan behind these guys driving about in plain-clothes cars, shooting at civilians," says Alan Johnson, then a detective constable. "If there was, it certainly escaped me. I couldn't quite grasp it, nor could any of my colleagues."

Detective Inspector Bill Mooney couldn't grasp it either. The MRF patrol's version was that Williams had been armed that day with the army's standard issue machine gun, the 9mm Sterling. Yet surgeons had removed 0.45 calibre bullets from the victims.

Eventually, the bullets were forensically matched to one of the two Thompson sub-machine guns in the MRF's armoury -- the one owned by MRF's last commanding officer Captain McGregor. Only then did Williams admit the truth -- that he had taken McGregor's Thompson from the armoury with him on patrol.

Eventually Williams and McGregor were charged with illegal possession of a firearm and ammunition. Williams was also charged with three counts of attempted murder.

That day the attorney-general, Sir Peter Rawlinson QC, is recorded as saying that McGregor's revelation that a Thompson sub-machine gun had been loaned by the Special Branch "might not be helpful" -- which was something of an under-statement.

He also told the then secretary of state, Willie Whitelaw, that "the whole case was extremely embarrassing and might become more so" because the "blue Cortina car alleged to have been used" by the MRF in the Glen Road shooting" had figured in other alleged crimes."

Sergeant Williams had indeed been involved in other controversial shootings, including the fatal shooting of Patrick McVeigh.

Officials then came under attack from ministers for not having been forewarned of "potential stinkers" like the Williams case which had "burst upon the Ministry of De-fence".

Why, ministers asked, had not "someone... pick(ed) up the potential dynamite in this particular case much earlier and warn us that it might be a particularly tricky one?"

But army HQ Northern Ireland had -- they just hadn't known how to defuse it which presumably explains why HQNI had not been "particularly helpful" and why the MoD in London was anxiously awaiting "what position would be adopted by the defence".

Particular concern was expressed about something in one of McGregor's formal statements described by the army deputy under-secretary as "horrific", warning of its "possible implications".

We can't say what so "horrified" him -- our Freedom of Information request for the statements was refused.

The firearms charges against McGregor and Williams were dropped.

Williams alone now faced trial charged on three counts of attempted murder. In London, the MoD scrambled around for "any legitimate diversionary tactic that might help" distract the press from identifying the MRF.

There was "considerable advantage in maintaining as much confusion as possible".

In the event, at his trial Williams did admit to the MRF's existence, but the damage to the army was significantly limited because the illegal firearms charges against him and McGregor had been dropped.

As a result of that, whatever explanation there might have been as to why Williams had a Tommy gun on patrol never emerged in court.

Williams told the court the only reason he had the Thompson with him was that he'd been on a firing range demonstrating it to new MRF recruits -- not an explanation we understand he offered the police.

Nor did the jury hear evidence from the major who'd spoken about knowing that Williams had been armed with a Thompson on previous patrols.

After a brief trial, Williams was acquitted on all counts by a majority verdict.

Both Williams and McGregor were eventually promoted -- McGregor ending his army career in 1998 as a brigadier, and Williams as a captain.

On September 27 1972, three months after the Glen Road shooting, another MRF patrol shot dead 18-year-old Daniel Rooney, telling the police he was armed with a rifle.

His friend Brendan Brennan, who the MRF said was armed with a pistol, was wounded.

Declassified papers show that the army briefed the secretary of state Willie Whitelaw that Rooney was a "volunteer in D Company, 1st Btn IRA" and that Brennan belonged "to the same gang as Rooney".

These claims are no more credible than the MRF soldiers' claims that their targets were armed.

As before, the swabbed hands and clothes of both youths showed no sign of having been in contact with firearms, consistent with eyewitness accounts that neither was armed.

Rooney does not appear on any IRA roll of honour, he is not buried in the republican plot in Milltown. There were no IRA death notices and his family and friends insist to this day he was not in the IRA; nor is there any evidence that Brennan was either.

When I called at the home of the soldier who shot Rooney he said that if I set foot on his "property again I'll punch you... and I can punch pretty hard".

In November 1972, a review of the MRF ordered by the army top brass found there was "no provision for detailed command and control" and said it should be replaced by a better-trained unit, which eventually morphed into 14 Intelligence Company.

Prime Minister Edward Heath sent a message to the army emphasising that "special care should be taken" to ensure that the new unit should "operate within the law".

An implicit recognition, perhaps, that some MRF soldiers' activities had been illegal?

The head of the army, General Sir Michael Carver, said the new training arrangements would "automatically reduce the risk of nonsenses".

Yet what had been the military logic behind those "nonsenses"? And why exactly had MRF soldiers sometimes been armed with IRA-style weapons?

In 1993, the RUC began a lengthy inquiry into the MRF's shooting of Patrick McVeigh.

Interviewed at his retirement home in Spain was the MRF's first officer commanding, a Parachute Regiment captain, Arthur Watchus, who had also served in the SAS:

POLICE: "Did you have knowledge of what weapons were being used in the car by patrols? How disciplined a unit was it?"

WATCHUS: "It was a disciplined unit but what they (his soldiers) did away from me, who can say?"

Watchus is now dead. So I asked his successor Captain Hamish McGregor if he had authorised Williams to take his privately owned Tommy gun on the day when Williams fired it at three men the police believed were unarmed.

McGregor declined to say but insisted the only reason that the MRF had Tommy guns in its armoury was for training, describing Williams as one of "our very experienced and respected operators" and pointing out that he answered to 39 Brigade, Belfast.

Commanding 39 Brigade for most of 1972 was Brigadier 'Sandy' Boswell, who ended his career as Lt Gen Sir Alexander Boswell, General Officer Commanding, Scotland. Did the MoD's verdict that there had been "no provision for detailed command and control" mean that lethal MRF operations were not under proper control? Boswell declined to respond.

Williams emigrated to Australia where we caught up with him. Opening his door, a burly, vested figure barked "I'm not interested" and then promptly closed it when I began to ask questions.

Meanwhile, McGregor wrote to say he ran "a pretty tight ship" with proper control over his men. He also complained that by publicising the claims of some of his former soldiers we were dignifying "unsubstantiated and fanciful theories".

Hunting down IRA members to shoot them would have been against the law and his soldiers had abided by the Yellow Card. He "remained very proud of the pioneering work we carried out in what was a very hazardous environment".

The MRF's work was indeed hazardous and pioneering. It was the prototype for more sophisticated army undercover units that penetrated and disrupted IRA active service units, reconciling the IRA leadership to the reality that an "armed struggle" would never force a British withdrawal from Northern Ireland.

As to 'death squads' -- a label paradoxically shared by nationalists with long memories and one of the two former MRF soldiers turned author -- Soldier D said: "I totally reject 'death squad'," only to pause and add: "Put yourself in my situation: we've got a dirty war, a war that was out of control. We knew who the operators were, we knew who the shooters were. So what are you going to do about it, John?"

Soldiers are not policemen. They are required to close on the enemy and, if necessary, to kill them, even if innocent bystanders are in their midst.

Some in the MRF seem to have had particular difficulty in distinguishing one from the other, inflicting grave damage to the reputation of the British army which could otherwise take credit for having fought -- and won -- an asymmetric war against terrorists.

Asked about the allegations that unprovoked, MRF soldiers shot unarmed civilians, the Ministry of Defence said it had referred them to the police in Northern Ireland.

Thirty years of conflict has a long tail.