A triple child killer who hung his victim's mutilated bodies on a fence outside their home has been cleared for release by the Parole Board.
Paul had been strangled, Dawn was found with her throat cut, and Samantha died from a compound fracture to the skull.
McGreavy, who was 21 at the time, then impaled their bodies on the spiked garden railings of a house in Gillam Street, Rainbow Hill.
McGreavy, a family friend and lodger, claimed he killed the children because one of them would not stop crying.
He was sentenced to three life sentences for the murders in 1973 and ordered to serve a minimum of 20 years.
The Parole Board confirmed that a panel directed his release following an oral hearing.
The children's mother Elsie Urry, who has also been known as Dorothy, told The Sun: "What this animal did to my children was every bit as bad as what the Moors Murderers did.
"But Ian Brady and Myra Hindley never left prison before they died so why the hell should he?
"He put my babies on spikes for God's sake - he mutilated them and they died in agony.
"I wanted him dead and to -suffer like they had but was reassured after his trial that his crime was so terrible he would never walk free again.
"But despite begging them to keep him locked up, I have now finally been betrayed."
A document from the Parole Board about McGreavy's case referred to a victim personal statement from the children's mother, "setting out the devastating effect that these deaths had on her and still do have".
The document said that over the 45 years in custody, McGreavy, who is now 67-years-old, has changed "considerably".
It added: "He has developed self-control, as well as a considerable understanding of the problems that he has had and what caused them.
"The psychologist identified a number of factors which make it less likely that Mr McGreavy will reoffend in future.
"These included his improved self-control and the fact that Mr McGreavy has learnt to remain calm in stressful situations.
"He has also shown himself to be compliant and co-operative with authority, which suggests that he will comply with licence conditions.
"A network of supportive friends in the community was also identified as a protective factor."
The Parole Board said: "We can confirm that a panel of the Parole Board has directed the release of David McGreavy following an oral hearing.
"Parole Board decisions are solely focused on whether a prisoner would represent a significant risk to the public after release.
"The panel will have carefully looked at a whole range of evidence, including details of the original evidence and any evidence of behaviour change.
"We do that with great care and public safety is our number one priority."