A grandmother murdered her daughter-in-law as part of a depraved plot to stop her moving 200 miles away with her grandson - and now the killer's son has custody of the child.

Heather Emmonds was jailed for 20 years for murdering her son's ex-partner Tina Casey amid fears she and the young boy would move from Holywell, North Tyneside, back to the Isle of Man.

After trying to poison her twice, the 58-year-old stabbed Ms Casey 15 times in the neck, head and body with a filleting knife, while her 10-year-old son played on his XBox upstairs.

Heather Emmonds, of Seaton Deleval, Northumberland (left) murdered her daughter-in-law Tina Casey (right) as part of a depraved plot to stop her moving 200 miles away with her grandson

Emmonds, of Seaton Deleval, Northumberland, then wrote confession notes telling her grandson: 'I really thought it was the best for you.'

Now, two years after the killing, Ms Casey's bereft family have revealed how Emmonds's twisted wish has come true because the son, now aged 12, is living with his father.

Tracey Wright, 48, from Douglas, Isle of Man, told The Sun: 'Sadly, my nephew remained with his father just as Heather wanted.

'I knew Heather had wanted to keep the boy at home with his dad but I never thought she would stoop to such a level.'

Ms Casey, 42, decided to move back to the Isle of Man - where she was born and grew up - in January 2013. She had split from Emmonds's son Keith - the father of her child - with whom she had an 'on/off' relationship.

Ms Wright said sister had been anxious and edgy at the time and had wanted to move home because Emmonds was constantly demanding to see her grandson.

Tracey Wright, Ms Casey's sister, has spoken of her family's anguish after Emmonds's son was given custody of the child

And, as she prepared to move, Ms Casey shared her fears over Emmonds' controlling behaviour.

On one occasion, Ms Casey told her sister that she suspected she had been poisoned after eating a chilli which Emmonds had made.

A few days later, in February that year, Ms Casey fell ill again after eating a Chinese meal. She again feared she had been poisoned.

Three days after confronting Emmonds about the situation, Ms Casey was murdered.

'I told her not to be stupid and that Heather would not do that. How wrong I was,' Ms Wright said.

Nine months later, Emmonds appeared at Newcastle Crown Court charged with murder.

During the case, it emerged that Emmonds had tried to poison Ms Casey twice by crushing sleeping pills into two of her meals.

She had then gone around to her home on February 3, where she attacked Ms Casey as she lay on the sofa.

After putting her hand over her mouth to stifle her screams, Emmonds threw a duvet over the body and told her grandson that his mother was asleep, the court was told.

Emmonds then went about her evening in the usual manner, dropping off her grandson to be with his father before going to play bingo.

But, the next day, she had a crisis of conscience. Police discovered Emmonds's body slumped in her car after she took an overdose of sleeping pills and crashed, the court heard.

Officers found the murder weapon and ten confession notes in Emmonds's Vauxhall Corsa.

One, written to her grandson, said: 'Please don't hate me for what I have done. I really thought it was the best for you. I will always love you.'

'I know it won't look like it but dad is a great dad for you so be good for him and Gramps.'

The court heard how Emmonds also considered setting Ms Casey's home on fire, with her body inside, to mask her actions, but that she was put off by watching crime dramas, saying she had 'seen too many CSIs to know it doesn’t really work'.

Ms Casey's body was discovered with multiple stab wounds at her home in Holywell, Northumberland

During the trial, Emmonds admitted stabbing Ms Casey but claimed she was not in control of her actions. But the jury found her guilty of murder.

After she was jailed for 20 years, the victim’s family said in a statement that 'no one had won'.

''We’re really going to continue to miss Tina, especially her children and the rest of the family, both now and in the future,' they said.

'No one has won in this case, both sides of the family have lost a mother, one has died and another is in jail, through tragic circumstances.

'Both sides in this case have shown great dignity and have conducted themselves impeccably throughout this trial.

'We’d like to thank the police for their support and Victim Support who have both helped the family through this very difficult time.