The court had previously heard evidence that gardaí found explosive device components in the man’s locker at Maynooth University.
Last month, Dónal Ó Coisdealbha, aged 25, of Abbeyfield, Killester in Dublin 5 pleaded guilty to membership of an unlawful organisation styling itself the Irish Republican Army, otherwise Óglaigh na hÉireann, otherwise the IRA, within the State on May 13, 2015.
Sentencing Ó Coisdealbha yesterday, Ms Justice Isobel Kennedy, presiding at the three-judge, non-jury court, said the evidence against the man was “significant” and even “overwhelming”.
The court previously heard from Det Insp William Hanrahan, of the Special Detective Unit, that in the months leading up to the royal visit, in May, 2015, Ó Coisdealbha and others were kept under surveillance by gardaí.
In January 2015, Ó Coisdealbha was observed at The Coachmans Inn pub in Swords, meeting with “a particular individual” who has a conviction before the Special Criminal Court and who is suspected of having a significant role within the IRA.
Further meetings occurred between the two men there in February, March, April, and May of that year.
On May 9, Ó Coisdealbha was seen in the company of two brothers driving to a house at Harbour Court in Courtown in Wexford. During a subsequent search of the house, gardaí found four improvised rockets, Semtex, a chord of cortex, and two detonators. A search was also conducted at Ó Coisdealbha’s workplace at Maynooth University on May 13. A time and power unit (TPU) and a broken circuit board were found in a locker which only O Coisdealbha, who worked in biomedics, had access to.
A TPU had also been found in the Courttown house. When both TPUs were analysed, it transpired they fitted together. O’Coisdealbha’s DNA was found on a pair of gloves in the Courttown house and also on an improvised explosive device.
Ms Justice Kennedy said the court paid particular attention to the fact Ó Coisdealbha used his intellect and educational skills to provide the TPU.
The court also heard evidence of audio recordings made by gardaí of Ó Coisdealbha and the other man. They met on May 10 and plans to develop an artillery rocket were discussed.
The court heard that it was clear from that conversation that preparations were well advanced and the indication gardaí had was that the event was to happen around May 19, when Prince Charles was visiting Ireland. The blame was to be given to a different organisation within the IRA.
Mitigating factors were his early plea of guilty, his lack of previous convictions, his remorse, and his educational abilities. Having regard to the gravity of the offence, the judge said, the court considered seven years an appropriate sentence.
Taking into account mitigating factors, the court reduced the sentence to five and half years in prison.
The sentence was backdated to May 30 last year.