The former provisional IRA leader Mr Murphy was found guilty by three judges in the non-jury court of failing to furnish tax returns for nearly a decade. The court heard Mr Murphy received 100,000 euros in state and EU subsidies.
A 2006 raid on Mr Murphy’s farm later led to a one million euro settlement with the Criminal Assets Bureau and its UK counterparts.
Deputy Ferris was speaking following comments from Sinn Fein Leader Gerry Adams on the case.
Mr Adams said Sinn Fein is strongly opposed to tax evasion, but also to the existence of the Special Criminal Court.
He said hearing the tax evasion case in the non-jury court was a breach of Mr Murphy’s constitutional rights.
Deputy Ferris said that he agrees with Gerry Adams: