The break-in at the Castlereagh police facility on St Patrick’s Day 2002 turned the security forces’ own intelligence hub into the target of a precisely planned raid. The thieves left with files identifying informants inside the IRA and other paramilitary groups, setting off an urgent effort to protect those whose cover might have been exposed and leaving the operation’s authorship contested.

A Fortress in Transition

Just after ten o’clock on a quiet Sunday night in East Belfast, three men in suits drove up to the gates of the heavily fortified Castlereagh complex. The Royal Ulster Constabulary had ceased to exist four months earlier under the Good Friday Agreement, and the facility’s policing role now belonged to the Police Service of Northern Ireland, whose new mission included more inclusive recruitment and a less exclusively Protestant association. The institutional change had not softened the site’s appearance: high walls topped with barbed wire still made it resemble a forward operating base, and it was reputed to be among Europe’s most secure buildings. Castlereagh housed police, the British Army and intelligence personnel. Only about twenty people were on duty across the compound that night. Its mixture of agencies and personnel, however, also meant that not every guard could be expected to recognize every visitor. The three men exploited that ordinary weakness in a place built to resist extraordinary threats: they presented what appeared to be army identification at the gate, were waved inside, and showed credentials again at the front desk. Both checks were passed without raising suspicion.

Their destination was not a public office but a room known as 2/20, the secret, round-the-clock nerve centre of the security forces’ intelligence network in Belfast. Hundreds of informants across the city could use its hotline to contact handlers in the police, the army and MI5. The operation had been moved temporarily because its usual office was being renovated, but the thieves knew where to find its replacement. That foreknowledge turned a daring intrusion into a carefully targeted raid on the network’s heart.

A lone Special Branch constable was manning the phones. When he opened the door, one of the men struck him hard in the jaw. The intruders taped his mouth, hooded him, tied him to an office chair and put headphones over his ears, playing music from a Walkman. They used keys left on the desk to open drawers and filing cabinets, taking documents while periodically checking that the constable was breathing. Once they stopped checking, he could not tell whether anyone remained in the room; when he eventually worked free and removed the blindfold, the men had vanished and the shelves were empty.

The stolen trove included notebooks and files containing informants’ details and code names, including people working inside the IRA and other paramilitary groups. The thieves had entered unmasked and unarmed, and nobody noticed them leaving. Their only apparent trace was a lapel badge left behind, bearing the words “SAVE THE RUC”—a detail that could have belonged to the disguise or been a taunt.

Fallout and Contested Authorship

The discovery triggered immediate alarm. Police contacted informants to warn that their identities might have been compromised and eventually relocated more than three hundred people. A security source described the break-in as “an act of war” and a wilful violation of the peace process. The IRA rejected responsibility, claiming instead that the operation was an inside job by the authorities. Most observers ultimately concluded that the Provisional IRA had carried it out, but the apparent precision of the raid suggested assistance from within Castlereagh: the thieves had known that the intelligence operation had been moved to a temporary location.

Investigators sought a Castlereagh cook for questioning because he was an associate of Denis Donaldson, a former IRA leader who worked as a Sinn Féin official at Stormont. That connection helped sustain suspicion of an insider, but it did not settle who had planned or executed the theft. One press report suggested that the goal might have been to identify a particular informer said to occupy an exceptionally senior position within the Provisional IRA. The name attached to the suspected agent circulated in several forms—Stakeknife, Steak Knife and Stake Knife—while the image remained that of a dagger at the heart of the organization. A 1999 account had called the supposed agent the crown jewel of British intelligence in Ulster.

The raid therefore became entangled with a larger, unresolved question: whether British intelligence had penetrated the republican movement at its highest levels, and who that agent might be. In March 2003, Dolours Price told a visitor at her Dublin home that she had heard the rumours but had not worked out the identity of the informer. In anger, she sometimes joked that it could be Gerry Adams, she acknowledged, but added that she did not think he was Stakeknife. Her uncertainty preserved the distinction between suspicion and proof. The stolen records made the danger of exposure concrete, while the suspected high-level spy remained a figure of rumour; the break-in intensified the search for an answer without conclusively providing one.

The Informant Question Beyond the Heist

The raid’s significance sits alongside a wider uncertainty about how informant allegations were made, recorded and later tested. In the investigation into Jean McConville’s disappearance, Nuala O’Loan found no official document fixing the precise date she was taken. A police log recorded that a woman identified as Mary McConville had been found beaten at 11 p.m. after being warned to stop giving information to the military; her address showed that the woman was Jean. The children remembered the warning and beating as occurring on 6 December, the night before their mother was abducted, but the log placed the incident on 29 November.

That difference mattered because the competing dates altered how the allegation against McConville could be understood. The family consistently placed her abduction in early December, while Brendan Hughes’s account described her as returning to informant work after a warning and being caught with another radio later. If the police log’s date was correct, more than one night could have separated the warning from her removal, making Hughes’s sequence more plausible; the record did not, however, settle what happened. The Castlereagh theft exposed the vulnerability of secret intelligence files, but neither the raid nor the competing recollections supplied a conclusive answer about every person suspected of informing.