Gardaí believe they know the identity of the prime suspect for the 2005 murder of Irene White and are confident of securing a third conviction.
A second man was convicted in the courts on Monday and sentenced to life. The remaining suspect is now the subject of an intense Garda investigation.
Garda sources described the third suspect as the "prime mover" in the case, at the "apex" of the murder conspiracy to kill the mother-of-three at the Ice House, Demesne Road, Dundalk, Co Louth, on April 6th, 2005.
They believe this third suspect was the man who wanted Mrs White dead and paid money for her to be fatally stabbed.
This third man has been the prime suspect since Mrs White was killed in a frenzied stabbing in her Co Louth home 14 years ago.
This suspect has an alibi for the time of the murder provided by unsuspecting people he was with at the time.
Monaghan man Anthony Lambe (35) of Annadrumman, Castleblayney, Co Monaghan, was jailed for life last January after pleading guilty to her murder.
On Monday, a second man, Niall Power (46), with an address at Giles Quay, Riverstown, Dundalk, Co Louth, was sentenced to life after pleading guilty to murder.
Power, a father-of-four, handed himself into gardaí last year, the day after Lambe was sentenced.
Power described himself to gardaí as the “middle man” in the conspiracy.
Gardaí believe Power was the link man between the third suspect or “prime mover” in the conspiracy and Lambe, who carried out the stabbing.
Gardaí believe the prime suspect directed and paid Lambe to carry out the murder, using Power as the conduit for instructions.
Mrs White was stabbed 34 times in the kitchen of her home. Garda sources have told The Irish Times the scene of the murder would “never leave” the officers and other emergency services personnel who attended that day.
Although the murder was investigated there was no breakthrough in the first years of inquiry. The case was taken over by a serious case review team in 2011.
In July the following year, a TV programme calling for fresh information led to an anonymous call to the Garda from a woman in Australia.
She said Lambe told her he murdered Mrs White.
In 2016 gardaí identified this woman, and two officers visited Australia to interview her.
Gardaí then spoke to Lambe's ex-girlfriend, who remembered the day of the murder because she flew with Lambe to England and he was "jittery and nervous". She put this down to it being his first time flying.
Lambe confessed after being arrested on January 20th, 2017, telling gardaí someone asked him to kill Mrs White on behalf of another person.
At the time of the killing Lambe was “in a very bad place”, drinking and taking drugs and in debt.
Lambe remembered stabbing Mrs White and cutting her throat before escaping over a wall. He also told gardaí he said a prayer over her body. He later telephoned the person who had asked him to carry out the murder and received a “relatively small sum of money”.
When Lambe was arrested he co-operated and confessed. After his conviction Power also confessed and has co-operated with gardaí.
Evidence they have supplied is expected to be used against the third suspect.