A 34-year-old Co Dublin man has been jailed for four years at the Special Criminal Court for membership of the dissident republican group the Continuity IRA.
Dermot Gannon gave a clenched fist salute and shouted: "Up Óglaigh na hÉireann" as he was led from the dock.
During the three-day trial the court heard Gannon was the leader of a weapons-gathering group in the CIRA and he controlled a number of weapons in Dublin in October 1999.
Members of the Special Branch found an Army uniform, a forged driving licence and four CB radios when they raided his home on October 16th 1999.
Gannon, of Wellview Cresent, Mulhuddart, is the first person to be convicted of membership of an illegal organisation under the 1998 Offences Against the State Act.
In its ruling the court accepted the evidence of Chief Supt Basil Walsh Gannon was an IRA member.
But the court held that the chief superintendent's opinion could have been formed after gardaí raided Gannon's home.
The court therefore ruled that the items found in Mr Gannon's home, as well as his refusal to answer Garda questions, did not form part of the decision to convict.
The court also said Gannon was given every opportunity to answer Garda questions during interrogation and the consequences of his refusal to answer questions was explained to him.
Mr Justice Frederick Morris, presiding, said Gannon had been convicted on the evidence of Chief Supt Walsh.
He said Mr Gannon could have weakened the effect of such evidence by giving his own evidence in court but had declined to do so.
Before sentencing Det Supt Peter Maguire said the IRA was not a homogenous organisation and Gannon was a member of Continuity IRA and remained so to the present day.