A 49-year-old man from west Belfast has been found guilty of the 2016 murder of prison officer Adrian Ismay.
Christopher Robinson shrugged as Mr Justice McAlinden said he was compelled to conclude he was "intimately and inextricably involved" in the dissident republican operation that led to his death.
After being handed a life sentence, the judge told Robinson he will determine the minimum length of time he will have to serve before being considered eligible for release at a later date.
As family and friends of Mr Ismay sat in the public gallery, Robinson was then led from the court in handcuffs by prison staff.
During the non-jury trial, it emerged that the two men knew each other as they had worked together as volunteers for St John's Ambulance.
The 52-year-old prison officer had just left his east Belfast home and was driving along Hillsborough Drive at around 7am on March 4 2016 when a device planted under his van detonated after he went over a speed ramp.
Despite appearing to make a good recovery from shraphnel injuries, the father-of-three died 11 days after the bomb exploded.
Robinson, from Aspen Walk in Twinbrook, was arrested two days after the explosion and denied any involvement.
During the course of 16 interviews he refused to answer questions, but in a pre-prepared statement he denied being a member of a proscribed organisation.
He was subsequently charged with murder, possessing explosives and providing property - namely a red Citroen CS - for the purposes of terrorism.
It was the Crown's case that the car, which was registered to Robinson's sister-in-law, was used to transport the improvised explosive device to east Belfast.
The prosecution made the case that evening before the explosion, he had picked up the Citroen from his brother's west Belfast workplace.
The claims were denied by Robinson, with his defence team making the case that the only evidence against him was circumstantial.
Arthur Harvey QC said the Crown had failed to prove its case beyond reasonable doubt and had failed to provide any evidence to establish a connection between the Citroen and Robinson "on the evening of the 3rd of March 2016 or the morning of the 4th of March, 2016".
Robinson had also denied being an "active member of the New IRA".
However, in a detailed ruling that took more than four hours to be delivered, Mr Justice McAlinden said he had examined the "individual strands of evidence" and concluded Robinson was guilty of the murder charge, and of possessing explosives with intent to endanger life.
The judge made "no finding" on the charge of providing property for terrorism.
His ruling highlighted several "key issues" which he felt required "specific consideration".
This included Robinson's DNA which was found on a Poppy Appeal sticker the judge ruled had been stuck on the Citreon's windscreen in a "cynical ploy" to make the vehicle transporting the bomb "less conspicuous in the area where the attack was to take place".
Another strand, he said, was Robinson's internet and social media activity both before and after the bomb blast.
Pointing out that he checked news sites a total of 80 times in a five-and-a-half hour period in the aftermath of the explosion, Mr Justice McAlinden said this demonstrated an "intense and enduring interest... that can only be explained by the defendant's prior knowledge of and intimate involvement in the planned attack"
Other points of relevance, the judge concluded, was Robinson's support for violent republicanism and republican prisoners.
The judge said his social media use also highlighted a "strong disapproval" of the PSNI, the Prison Service and Sinn Féin.
Mr Justice McAlinden said this provided a "cogent and compelling explanation for his intimate and inextricable involvement in the attack upon Mr Ismay".
Regarding the murder, the judge said it was his view that Robinson "arranged for and facilitated the use of his sister-in-law's motor vehicle for the purpose of transporting the bomb and bomber to Hillsborough Drive, and for the purpose of transporting the bomber away from the scene again".
He concluded by saying the evidence in the trial established "beyond a reasonable doubt" that Robinson was "intimately and inextricably involved" in the terror plot that resulted in the death of Adrian Ismay.
Detective Superintendent Richard Campbell later welcomed the guilty verdict and said his thoughts "are first and foremost with Adrian’s grieving wife, his three children and wider family circle who are still coming to terms with the pain and loss they feel every day".
"I hope today's conviction will provide some comfort for Adrian’s family. It should also serve as a warning to anyone involved in terrorism within our community that the PSNI will investigate these offences robustly and vigorously to bring offenders to justice."
