A 34-year-old man who was convicted of the manslaughter of his partner after claiming she had stabbed herself has been sentenced to 12-and-a-half years in prison.

Martin Hayes, from Poddle Close, Crumlin in Dublin, had pleaded not guilty to murdering Amadea McDermott at her home on Rathvale Drive, Ayrfield, Coolock, in July 2017.

He was found not guilty of murder but convicted of manslaughter at his trial earlier this month.

Mr Justice Paul McDermott said Hayes had shown no remorse for killing and through his own evidence at the trial had shown his underlying violent disposition.

The judge said Hayes was "violent in language and action" and there was self-deception in how he treated his partner and the mother of his children.

He said it was rare to be given such a clear demonstration of someone's character in a trial that was "shockingly clear" to all except himself.

During the trial, Hayes, who worked as a gravedigger, had admitted using violence against the 27-year-old woman and told the jury he had used a hidden app to track and access information on his partner's phone.

The trial heard that the couple's relationship was "difficult, volatile and abusive".

Judge McDermott said Hayes tracked Ms McDermott's phone and was determined to know every contact and content.

The judge said he had an unhealthy obsession and preoccupation in a completely untrue and unfounded belief that she was in a relationship.

Martin Hayes

Six years after Ms McDermott's death, a girlfriend of Hayes gave a revised statement to gardaí, telling them that the defendant had confessed his involvement in the killing, telling her he had "helped" her to push the knife into her stomach.

In his charge to the jury, Mr Justice McDermott said that if it accepted that Hayes inflicted the fatal wound without intent to kill or cause serious harm to Ms McDermott then it should find him not guilty of murder but guilty of manslaughter.

The 12 jurors took more than 13 hours over four days to reach a verdict of manslaughter.

Mr Justice McDermott rejected a defence submission that the verdict could have been consistent with some sort of accidental killing.

In victim impact statements to the court last week, Ms McDermott's family described Hayes as a deranged, cowardly predator and an abuser.

They said Ms McDermott was under coercive control and urged other victims of domestic abuse to stand up and be heard.

In a statement afterwards, Ms McDermott's family said today had been a long time coming for their family.

They said "a verdict is just a verdict and a sentence just a sentence and no amount of time could compensate for the life stolen from Amadea who was 27 years of age".

Her sister, Eucharia McDermott, who read the statement on behalf of the family said, "we will remember you as kind, caring, funny, loving, beautiful and amazing mother, daughter, sister, auntie and friend."

The family thanked the jury and the judge along with the prosecution team and investigating gardaí for their "constant and consistent work ethic, commitment, patience professionalism, determination and support."

She added: "They have been by our side and at the other end of the phone from day one when they took over this case... I cannot put in to words how grateful we are for the teamwork that helped convict this violent, sick, evil twisted, deranged monster."

She said: "This monster stood trial and told lie upon lie without a shred of evidence throughout the trial. He showed no remorse for taking our beautiful sister's life away from her and her family. He stood on trial, quite proud of his actions as he listed the amount of bruises one by one on my sister's body, as if he was keeping count."

She described him as "a sick, violent and evil monster".

"While he was cross examined by Sean Gillane the coward, thug and abuser was quite confident and proud, quoting 'if somebody hits me, I'll hit them back. I have every right to do so. Does this only apply to women?"

"Unfortunately, we will never get our beautiful Amadea back...the physical abuse, mental abuse and emotional abuse our sister endured and her violent death will haunt us until the day we pass...for every wound there is a scar, and every scar tells the story.

"We would strongly urge our nation to stand up against coercive or domestic abuse either being physical abuse, mental abuse or emotional abuse. We feel the laws in this country are too lenient and need to be changed urgently to help protect and save lives.

"On behalf of our family. Thank you to our friends, neighbours, schools, teachers, clubs and community for their continued support throughout this tough time. It will always be remembered and greatly appreciated that you've collectively got us through some tough, dark times and we will be forever grateful.

"To our sister's beautiful kids, warriors are the words that we describe you as your strengths and resilience inspires us every day. We know your Mam is beaming down with pride.

"To our Mam at home who cannot be here today due to health reasons, we commend your strength and we love you dearly. No mother should ever have to bury her child, especially under these circumstances, in a violent way.

"Our beloved Amadea, your life was taken from you violently and way too young. We cherish the years we had together and all the memories we have... we love you dearly and forever."