Two prison officers went to intervene. Unbeknownst to them, one of the attacking prisoners had a weapon — a blade melted into the handle of a toothbrush. This became apparent to the officers once they began to intervene, but by then it was too late to pull back. Both showed bravery in tackling the armed prisoner. One of the officers got slashed just below his thigh. The wound was about a foot long and an inch deep. It required 15 stitches.

The incident raised serious tensions in the prison. Violence is a part of life in prisons, but when a prisoner assaults and wounds a member of staff, the reaction among staff is of a completely different order than would pertain following prisoner-on-prisoner violence. A few hours later, the governor addressed the staff to keep everything on an even keel.

There followed two separate investigations. When a prisoner transgresses, he or she is subjected to a disciplinary process within the institution. The report is known as a P19, is compiled internally, and sanction applied as deemed appropriate. This would typically involve loss of privilege or redeployment within the prison.

In the case of the assault, there was a body of evidence. Apart from the testimony of the injured officer and his colleague, there was CCTV footage. This is understood not to have been conclusive, but definitely was probative in compiling evidence. There was also the evidence of other prison officers in the vicinity, particularly those who intervened to assist their colleagues.

Apart from that, the prisoner actually admitted his role. He is reported to have expressed remorse in an interview, and asked that his regret be conveyed to the injured officer.

The disciplinary report was effectively an open and shut case, and the prisoner was disciplined.

The injured prison officer recovered from his wounds and, according to prison sources, returned to work promptly. “He was brave in what he did and he came back to work before he would have been expected to or had to,” one source said.

The criminal investigation was the other process that was to follow the assault. Naturally, this involves the gardaí. A criminal investigation was conducted and a report sent to the DPP, who directed that no prosecution was to be pursued. There was not sufficient evidence to bring charges.

Within the prison, there was some bafflement at the result. How could there not be enough evidence?

The Irish Examiner understands the Garda investigation did not include as an exhibit the S19 report in which the prisoner effectively admitted his role. The Garda investigation definitely did not include extensive interviews of the prison officers who were present at the incident. One among them was a man referred to here as the whistleblower.

He is the prison officer who the Irish Examiner recently reported has received €30,000 from the Workplace Relations Commission over treatment he received as a result of making a protected disclosure. His disclosure concerned work practices and what he saw as ill-treatment he received as a result of raising concerns.

The whistleblower was never interviewed by the gardaí or the prison authorities, despite being a witness to the assault. The failure to ask him what he saw was referenced by Judge William Early, who examined his protected disclosure. The whistle-blower claimed the failure to interview him was symptomatic of the isolation to which he claimed to be subjected.

Judge Early reported: “The discloser was the officer in charge of the area where the incident occurred and participated in the restraint of the violent prisoners. An explanation for failing to interview the discloser is that there was excellent CCTV film of the events.” However, the judge was not impressed.

“The incident of March 2015 suggests a serious criminal offence was committed… it is quite extraordinary that a primary witness to a serious assault was not interviewed.”

According to sources in the prison service, the failure to interview the whistleblower for the disciplinary process was not unusual.

“It mightn’t have been considered necessary,” one source said. “There was CCTV, but even more to the point the prisoner admitted his guilt. So maybe he just wasn’t needed.”

However, the failure of the gardaí to interview the whistleblower raises questions. Their case for bringing charges quite obviously was not robust, as it was rejected by the DPP.

The apparent failure to seek access to and include the disciplinary case in the Garda file raises more questions. This file contained an admission from the prisoner about his guilt. Surely that was of immense importance to an investigation into an armed assault on a frontline worker, particularly as much of the other evidence must have been flimsy, as it was rejected by the DPP.

The injured officer was outraged at the DPP decision. He wrote to the director’s office, pointing out the failure to interview the whistleblower and other aspects of the case that he believed were not properly investigated.

“My colleague is anxious to furnish a statement with regards to the serious assault which was perpetrated on me,” he wrote. “I am also troubled by the blanket term ‘lack of evidence’. In my view, and that of legal professionals, substantial evidence was collated by the gardaí and was also in possession of the Irish Prison Service. I would be most grateful if you could outline the lack of evidence given to your office and by whom, as obviously the ‘system’ has failed me thus far.”

On October 7, 2017, the prison officer was informed that the case had been referred back to the gardaí by the DPP for further investigation. The officer was re-interviewed nearly three months later on December 3. He says he was told the delay was due to the fact that the investigating garda had got married and had been on honeymoon.

So far, the whistleblower has not been interviewed by the gardaí about an assault that it now three years old. The Irish Examiner understands the disciplinary report has not yet been requested as part of the evidence- gathering process. “I’ve been left in limbo because I feel that the gardaí are simply not interested in pursuing this assault on me,” the prison officer said.

The failure to interview the whistle-blower appears inexplicable. There is no suggestion that there is any agenda within the gardaí actively disposed towards not bringing a prosecution.

However, nor is there any sign that a case involving an assault on a frontline worker is being treated with the urgency it deserves. Inquiries about the case to the Garda press office were not answered at the time of going to print.