Edward McDonnell was arrested for possession of the weapon in 2019 by gardai who suspected him of involvement in a revenge plot for the murder of Sean Little.
In August 2020, McDonnell (57) of Waterside Apartments, New Ross, Co Wexford, was sentenced to nine years' imprisonment by the Special Criminal Court for unlawful possession of a Grand Power G9 semi-automatic pistol, at Lein Park, Harmonstown, Dublin 5, on September 14, 2019.
His co-accused, Stephen Little (48) of Kilbarron Avenue, Kilmore, Dublin 5, was sentenced to six years' imprisonment for the same offence.
Little's son, Sean (22), was found shot dead beside a burning car near Balbriggan off the M1 in Dublin on May 21, 2019.
Little had told gardaí after his arrest: "Had you given me another hour, I would have killed the bastard that killed him [Sean]".
The court heard that had Little not made these comments the case against him would have been weaker and he may not have been charged.
The Special Criminal Court heard during the sentence hearing that gardaí recovered a loaded handgun under the passenger seat of an Audi car, which they had under surveillance, on the day before McDonnell was forcibly removed from the vehicle. Little had driven McDonnell to the scene.
A number of items, including two baseball caps, two balaclavas and some gloves fell from McDonnell's lap upon arrest and a red petrol can containing liquid as well as a long-handled lighter were also found in the vehicle.
Both men had been originally charged with having the weapon with intent to endanger life. However, the two were jailed for possession of a firearm in suspicious circumstances, an offence under Section 27A (1) of the Firearms Act after guilty pleas were entered.
On Thursday at the Court of Appeal, Michael Bowman SC, for McDonnell, argued that the disparity between the two sentences amounted to an error by the Special Criminal Court in the sentencing of his client.
Mr Bowman said that while McDonnell had taken a date for trial he had pleaded guilty after the prosecution had rested their case. Mr Bowman said that McDonnell received a 10 per cent discount on the headline sentence of 10 years while co-accused Little received a 25 per cent discount on a headline sentence of eight years, reducing his sentence to six years in jail.
Mr Bowman said that McDonnell was not involved in any organisational or motivational way, compared to Little, who he said was "the prime mover" and someone who "did better" when it came to sentencing.
Mr Justice George Birmingham said that while Little did better in terms of sentencing he did not see how it assisted the appellant, McDonnell.
Mr Bowman said that while McDonnell had 47 previous convictions the "vast" majority were related to road traffic matters and that he had been "corrupted" at a young age due to his use of heroin at 19.
Mr Justice Birmingham said the possession of the pistol was of "the utmost seriousness" and that "I would have been thinking double figures [in terms of sentencing]".
Mr Justice Patrick McCarthy said that 14 years' imprisonment was the maximum jail term for the offence and that the nine years received by McDonnell could be seen as "lenient".
Regarding the appellant's argument of parity of sentence, Mr Justice Birmingham said Little had suffered a tragedy, had pleaded guilty at an early opportunity and had no relevant previous convictions.
Mr Justice Birmingham said the position of the two men was "therefore markedly different" and taking into account the 47 previous convictions McDonnell had amassed, he said: "He [McDonnell] did well."
In delivering the court's ex tempore judgement, Mr Justice McCarthy said McDonnell only pleaded guilty on the fifth day of his trial. The court noted that the weapon was in good condition, with 12 rounds of ammunition found in its magazine.
He said McDonnell could not benefit from the same mitigating factors as Little, namely the death of his son, lack of previous convictions bar one for a road traffic offence, positive testimonies and the early admission of guilt.
Mr Justice McCarthy said there was "no basis in the disparity being unjustified" and noted that McDonnell, unlike Little, made no admissions to gardaí before his trial.
The judge added that McDonnell had convictions for robbery, attempted robbery, sexual assault and assault causing harm and that he enjoyed no mitigation on any evidence of having past good character.
In dismissing the appeal, Mr Justice McCarthy said that both McDonnell and Little were "fortunate" that the Special Criminal Court did not identify a higher headline sentence.