The killer of Officer Jerry McCabe is being questioned; his wife, former Sinn Fein member, is in critical condition.Thinkstock

Irish Republican and notorious murderer Pearse McAuley was arrested on Christmas Eve and is being held for questioning regarding the violent stabbing of his wife Pauline Tully-McAuley in their Co. Cavan home on Wednesday night.

The former IRA member previously served ten years in prison as one of four men who pleaded guilty for the 1996 killing of Garda (police officer) Jerry McCabe in Limerick during a post office van robbery attempt.

Pauline Tully-McAuley, a former Sinn Fein councilor, suffered several stab wounds including a punctured lung, and was rushed to a nearby hospital for emergency surgery where she is in critical condition and currently being treated, said the Independent.

A source said the scene of the crime was extremely bloody, and that Pearse McAuley had tried to run away from Gardai (police) before he was arrested in Kilnaleck, Co. Cavan.

Pauline Tully-McAuley, a secondary school teacher and mother of two, gave up her Sinn Fein chair to concentrate on her family and teaching career. The Sinn Fein Party will not comment on the incident; a spokesperson told the BBC that it is a matter for the Gardai, and they do not want to compromise the investigation in any way.

The bloody scene at Kilnaleck was preserved and is pending a full technical examination.

McAuley’s 1996 prison sentence for McCabe’s murder was originally 16 years, but charges were dropped after ten years when witnesses refused to testify against him, presumably due to IRA intimidation.

McAuley and the three other killers, Michael O'Neill, Jeremiah Sheehy and Kevin Walsh, were admitted to Castlerea Prison in Roscommon as IRA prisoners, and Sinn Fein fought a campaign for their release as part of the peace process, the Independent said. The men were given favorable jail treatment in a low-security area known as “The Grove,” where Tully-McAuley and McAuley conceived their son, Pearse Jr.

McAuley was granted temporary release in January 2003 to marry Pauline Tully, which caused national uproar. The two had met while she was on a Sinn Fein delegation to meet Garda McCabe’s killers in Castlerea Prison.

At the time of his release in 2009, McAuley was wanted in Britain, as he had escaped London’s Brixton Prison in 1991 while awaiting trial for conspiracy to murder and possession of explosives. The UK’s Crown Prosecution Service announced it would not seek his extradition upon his 2009 release.