Sharon McKenna is remembered as something of a Good Samaritan by her family and circle of friends in north Belfast, who speak of an outgoing young woman who was generous and made friends easily. North Belfast is a tough place, which during the Troubles saw more deaths per square mile than any other area. Many people avoid it, while those who live there carefully watch where they go and veer away from its many dangerous districts.
Sharon was slightly unusual in that she drove a taxi-cab around the whole area, often at night, as well as taking part in a CB-radio network that included both Catholics and Protestants.
She had friends in both communities, her gregarious nature leading her to put friendship before precaution. Her mother recalled: "I'd say to her, 'Watch yourself, with these old troubles going on.' But she'd just say, 'No one would want to bother me.'"
Sharon was Catholic, and on the night of her violent death she was cooking a meal for an older Protestant man, a family friend who was home from hospital. He would later recall her as a "generous and kind young woman".
The two loyalist gunmen who forced their way into the house first demanded her car keys. Then, without warning, one of them blasted her with a shotgun. As she lay helplessly on the floor he fired again into her body.
At her funeral, a bishop said she was killed, "because she crossed a divide to help a friend," adding: "She dared to cross... barriers, barriers erected by those who wanted a particular area to be a no-go area for those who differed from them in religious belief."
At first, her death seemed to be one more of the relentless stream of north Belfast sectarian killings. Sometimes the police secure convictions for these, sometimes not: no one was charged with McKenna's murder.
Very often detectives reckon they know who carried out such attacks, but very often they say they cannot prove it, and the guilty go free: the phenomenon is a familiar fact of paramilitary life in Belfast.
Yet the extraordinary and appalling facts behind the McKenna killing, and behind at least nine other Belfast murders, have just been exposed to public gaze in a breathtaking report released yesterday by Northern Ireland's Police Ombudsman, Nuala O'Loan.
The document cements O'Loan's reputation as a woman with the tenacity to dig out concealed details behind some murky facets of police work, whatever forms of obstruction are placed in her way.
The report on the deaths of Sharon McKenna and others centres on the activities of the Special Branch of the Royal Ulster Constabulary, which has now been replaced by the Police Service of Northern Ireland.
In this case, the investigation was hampered by the fact that many documents disappeared before and after the O'Loan inquiry got under way. Most of the officers she contacted failed to reply, while others, she said, gave answers that were untrue, or "evasive, contradictory and on occasion farcical".
Yet there was enough testimony, and enough documents survived for her to construct a detailed account of the shooting and its aftermath.
Central to the story was one of the gunmen, a particularly unsavoury character named Mark Haddock, who was involved both in the drugs trade and in the paramilitary Ulster Volunteer Force in the loyalist stronghold of Mount Vernon.
Haddock, referred to in the report as Informant 1, was at that point an informer for the CID and the Special Branch. In what seems an incredibly trusting move on the morning after the McKenna killing, Haddock told a CID officer he was one of the two gunmen involved.
Quite apart from this admission, Special Branch recorded other information showing Haddock was involved, along with others. This intelligence meant he had to be questioned about the murder, so he was detained.
He was interviewed 37 times over a six-day period, but made no admissions. Those questioning him were aware that he was an informant and knew he would say nothing: one detective said he "felt like a gooseberry" sitting in on the futile question sessions.
In fact, one of the detectives interrogating Haddock was actually his CID handler, another officer feeling he was "just going through the motions". The O'Loan report concluded: "These interviews were a sham."
Police involved have provided conflicting versions of what happened, and various Special Branch intelligence reports relating to the murder cannot be found.
The report found that while Haddock is a main suspect for the McKenna murder, he has not been properly investigated for it. And there is no record of anyone querying the wisdom of having retained a prime murder suspect as an informer.
For some reason, Mark Haddock was given a pay rise after Sharon McKenna was shot. He had been earning £100 a week, but soon after the killing this rose to £160. Over the course of a decade he made £80,000, before ceasing to be an informer in 2003.
It is not clear what he did for such payments - or whether he was paid even more, for some monies were never recorded or had been destroyed. On one occasion he was paid £10,000, but as Mrs O'Loan said, "nothing is known about why this payment was made, how, or who authorised it." There is no indication that he regularly produced life-saving intelligence.
In his early days as an informer, Haddock had, it seemed, saved one life, as informers are supposed to do. This is the justification for keeping such people on the books: it is a grey area both legally and morally.
In Northern Ireland, on both sides, everyone knows informers are not people of sterling character. The theory is that they must inevitably break the law to maintain their positions within underground groups, but that such law-breaking should be kept to an absolute minimum.
Yet in Haddock's case, his status as informer, in effect, gave him carte blanche to become what an investigator yesterday described as a serial killer. Surviving records show Sharon McKenna was one of many victims in a career that has put him among the most active loyalist assassins.
He is believed to have been involved in 10 killings. His victims include half a dozen murders of Catholics such as Sharon McKenna, all of which appear to be sheer sectarian killings of people who were not politically active.
Four other men were killed in internal loyalist disputes, including the son of one of Northern Ireland's most remarkable men, Raymond McCord. His son, also Raymond, had the misfortune to become mixed up in a cannabis deal with Haddock in 1997, and was battered to death on Haddock's orders.
McCord senior is a striking example of the Belfast tradition of hard men who settle disputes with their fists. Years ago, when he discovered Haddock had had his son killed, he repeatedly named him in media interviews, unafraid of UVF death threats.
Although he is probably the city's champion bare-knuckle street-fighter, McCord was overcome several years ago by a gang of loyalists who set about him, breaking his legs and putting him in hospital. But he continued to issue statements accusing Haddock of having his son killed and of being a high-level police informer.
He told The Independent at the time: "This man is a drug dealer, extortionist, Special Branch agent, who has been allowed to get away with murder. He has been involved in many murders, and he has been totally immune from prosecution."
For years, his charges seemed incapable of independent verification, for the police and other agencies would not confirm whether anyone was an agent.
Yet snippets emerged that tended to support the McCord allegations, and eventually a former police officer turned whistle-blower also alleged Haddock was an informer.
McCord's decision to take his case to the Ombudsman that eventually produced firm evidence that Haddock had been allowed to get away with murder.
The 10 killings do not exhaust the list of wrongdoings with which he has been associated, for there are five more deaths in which he may also have been involved. He and his associates are also believed to be linked with five more attempted murders, 10 "punishment" attacks and activities such as criminal damage, extortion and intimidation.
To this can be added drug-dealing actitivies, for which he had a conviction. The files reveal 17 instances of Haddock selling drugs: on two occasions he admitted to handlers he was into the drugs trade. He did pass on to the police information about other drug-dealers - including some associates - apparently to have them arrested so as to create a bigger market for himself.
O'Loan collected 70 separate reports implicating him in drug-dealing, but when she interviewed Special Branch officers, "the vast majority" said they were unaware of such activity.
Drug money formed a major part of the revenues of the violent loyalist groups. The report includes her terse comment that she "does not accept that the officers were ignorant of Informant 1's drug-dealing". Her conclusion is that the Special Branch disregarded most of Haddock's drug activities, an attitude which she describes as collusion.
In past few years, Haddock's life has been eventful and hazardous. First, he and associates attacked a Protestant man with a hatchet, knife and baton, inflicting a fractured skull and multiple lacerations. When he was released on bail on a charge of attempted murder he arranged a meeting with his UVF associates, apparently to reassure them that the reports that he was an informer were untrue. When he showed up, he walked into a mafia-style hit, his former mates shooting him six times.
He quickly recovered, but towards the end of last year was jailed for 10 years for the previous attack on the Protestant man. He is due for release in a few years, but as those six bullets indicate, he will, if he remains in Northern Ireland, be a dead man walking.
Many questions are unanswered. How many other Haddocks have there been? This report concerns only one north Belfast housing estate where the UVF has a presence; there are dozens more districts infested by UVF "teams" or "units".
If the Haddock pattern is repeated elsewhere, then the number of loyalist killings that may merit reinvestigation could spiral into the hundreds.
The impression is that the secret world of the Special Branch was beyond any meaningful accountability, with police chiefs fending off outside inspections by arguing that Belfast's problems were so severe that normal rules simply could not apply.
When O'Loan's investigators asked for written material, they found that parts of murder files, decision logs and intelligence documents were missing. This she judged "a deliberate strategy which had the effect of avoiding proper accountability". Although this has not prevented her producing a searingly critical report, the lack of specifics almost certainly means that prosecutions of individual officers can never be brought. Haddock's activities were clear to his handlers, the sergeants and constables, but the entire system, in her opinion, could not have operated without "the knowledge and support" of the highest levels of the police.
The Special Branch could perhaps answer some of the outstanding questions, but it has clammed up and closed ranks. Special Branch had six heads during the time in question: none would speak to O'Loan.
Almost all of the officers who have fallen under suspicion, or have refused cooperation, have left the police service, and many new safeguards and structures are said to be in place.
The Ombudsman's investigators now express a high degree of confidence that a "proper and ethical" system is in place and that the present Chief Constable, Sir Hugh Orde, reacted quickly and decisively when they told him some years ago what had gone on in his force.
None the less, although this is in one sense merely the latest in a line of revelations, it is one of the worst cases of police misbehaviour and one that yesterday produced widespread shock.
O'Loan, in a repeat of previous revelations concerning the Special Branch, discovered that it almost routinely refrained from passing on vital information to CID detectives investigating murders. In one case, Haddock was questioned about a killing but the interrogations were conducted by his handlers. They knew he was involved, but "babysat" him through the interviews, later handing in notes that did not reflect what he said.
In another double murder of two Catholics, Haddock was one of the suspects. The gunman was said to have had a goatee beard. Haddock had one, but was allowed to shave it off in custody.
The report has many more such snippets, together with allegations of practices which, together, are said to constitute collusion. These range through concealment, misleading documents and the production of misleading material for the courts.
One accusation has not been stood up, for the report found no hard evidence that the Special Branch knew some people were being targeted by Haddock and the UVF, and allowed them to die. Yet although this is true in terms of specifics, the generality is that the Branch protected Haddock, even though it knew he was repeatedly involved in killings. It kept him out of prison and on the streets, it turned a blind eye to money-raising drug activities, and paid him well.
The Branch did not know he planned to kill Sharon McKenna, the cheerful girl who paid with her young life for her efforts to cross the sectarian divide. But after her death, they certainly knew he would murder again, and they did nothing to stop his decade-long killing spree.
Victims who justice betrayed
24 February 1991
A 26-year-old Catholic voluntary worker, he was shot by the UVF in the living room of his home. His three-year-old niece was injured in the attack. Two men, one with a sledgehammer, shot him through the window before entering the house and shooting him again as he lay on the floor.
24 February 1994
A 55-year-old married Catholic with four children, he was shot by loyalists while babysitting four grandchildren at his daughter's house. He was wounded in the neck and died in hospital a week later. He had recently had his voicebox removed during an operation to remove throat cancer.
17 May 1994
A Catholic building worker, he was living with his girlfriend and child at the time of his murder by the UVF. Convie was described as a "happy-go-lucky" person who was a member of a Gaelic Athletic Club.
17 May 1994
A 44-year-old Catholic who was married with six children, he was shot by the UVF with Gary Convie as the two were eating their lunch in a car near a building site where they were working. The gunman fired from a children's playground, using its railings to prop up a Sten sub-machine gun.
17 June 1994
A taxi driver aged 27, he was shot by the UVF after picking up two men. A witness said the killers got out of the car and spoke to their victim briefly before shooting him three times with a pistol. Brady was hit twice in the head and once in the back. He and his partner had two children.
21 March 1996
A Protestant with links to the UVF, he was in a bar when two gunmen wearing scarves to conceal their identities kicked open the doors and singled him out. One of the gunmen opened fire, hitting Sheppard three times in the head and body.
19 May 1997
A Protestant, he was found beaten to death in an alley on the Mount Vernon estate, where Mark Haddock lived. Harbinson had been handcuffed. His death was originally classed by police as a "domestic" incident, rather than one with paramilitary overtones.
9 November 1997
A 22-year-old Protestant who had been a member of the RAF for four years, his body was found in a quarry. His father mounted a campaign claiming his death had been ordered by Mark Haddock, who he claimed was being protected by Special Branch as an informer.
31 October 2000
A loyalist figure who had been involved in political talks, he was shot in his home after four masked UVF men forced their way into the house, beating his wife when she tried to stop the attack. Their three children, who were celebrating Halloween, also witnessed the killing.