The first murderer to be jailed after an amendment to the 800-year-old double jeopardy law has said he would have killed or committed serious violence again, but today “I totally get” the suffering of the victim’s family.

William Dunlop, now 63, strangled Julie Hogg in Billingham, County Durham, in 1989 and hid her mutilated body behind a bath panel.

Miss Hogg’s mother, Ann Ming, discovered her body there more than two months after her death.

The killer had subjected the 22-year-old pizza delivery woman, who had a three-year-old son at the time, to a violent sexual assault after she rejected him, in what prosecutors called a “premeditated and truly horrendous” attack.

On Wednesday, Dunlop started his fourth application to review his case and the panel will consider his release as well as potential transfer to another prison.

The Parole Board has recommended his transfer to open prison multiple times but three justice secretaries have intervened, the panel heard.

Miss Hogg’s son Kevin recounted his childhood trauma of “hearing screaming and shouting in the home with the pungent smell of my mother’s decomposing body” as his grandmother found it.

Opening the review of Dunlop’s case, he said: “I can say categorically that time isn’t the great healer it’s purported to be.

“As the years pass, the pain of losing my mother to this murder remains acute.”

After the statement, Dunlop, who psychiatrists previously found has “psychopathic traits” and “severe personality problems”, told the panel: “With my significant bereavement that I had, I can empathise with them (the family).

“I get it now. I totally get it now.

“I was struggling when (Mr Hogg) was talking about it, from what it was bringing back for me.”

The panel later heard the recent bereavement was his son.

Dunlop said “if I think about my significant other, I think about Julie” and “this is going to be the most difficult parole hearing I have been in”.

He added: “I can’t understand (Mrs Ming) finding her daughter, that I struggle with, but I relate to the loss now, the not knowing – I get that, I really do.”

The killer described getting “snippets of information” about his son’s death while in prison.

Per Dunlop’s request to not be seen, the murderer spoke with his back to the camera that was live-streaming from an unnamed prison to a room with Miss Hogg’s family inside.

Dunlop, known as Billy, was tried twice for the murder but both juries failed to reach a verdict.

Three years later, while in jail for another crime, he confessed and admitted lying in court, boasting there was nothing anyone could do about it because of the double jeopardy rule in place at the time.

Miss Hogg’s family, including her mother, campaigned for 15 years to get the law changed so he could be charged with the same crime twice, and in 2006 he became the first person to be tried under the new rules.

He admitted murder and was jailed for life with a minimum term of 17 years.

Panel member Zaiada Bibi asked him if he regrets the confession and he responded: “No, no, without a doubt, no.

“I think I said this at the last parole that I thanked Mrs Ming for doing it because I’ve not hurt anybody else – by me being in prison all this time I’ve not hurt anybody.”

Asked if he believes he would have gone on to commit another murder or serious violence, he said: “I would say yes because that’s what my life was.”

Dunlop said he started using violence at seven or eight-years-old because he was “taught that’s how you got respect”, and that remained his “identity” until 10 years ago.

He said he had intended to take Miss Hogg’s life because “you cannot strangle somebody and think you’re not going to do that”.

The killing was motivated by his “entitlement and also the rejection, because I’ve never handled rejection very well at all”, he said.

Asked what he thought he was entitled to, Dunlop said: “Respect. ‘You should respect me’ was one of my unwritten rules.”

“Euphoric feelings” hit him for up to 30 seconds after he realised Miss Hogg was dead, he said.

The euphoria was about “the power it gave us because I’ve always felt insecure”, he added.

Dunlop said he then started to panic and “I just thought ‘what have I done, what am I gonna do’, and I just thought ‘I can’t get caught for this'”.

He said he sat in the chair across from Miss Hogg for what could have been five minutes or half an hour before moving the body.

The panel asked if he thought about the impact of his crimes on the family prior to the parole hearing.

Dunlop, who now works as a painter and decorator in prison, replied: “I did think about them and the effect it would have on them, however it was all about me and I just suppressed what I felt.

“I just pushed it to one side and I had seen them on the telly, Ann and Kevin, when she was missing and I either turned it over or turned the volume off because I couldn’t – it was all about me, it wasn’t about them, it was survival.”

Dunlop went on to say he would not have confessed if the double jeopardy law was not in place.

“I would have tried to carry on suppressing it,” he said.

Describing his personality at the time of the attack, he said: “I was just a selfish individual who just thought about myself, who didn’t a lot of the time think about others – it was all about my needs, it was all about what I needed.”

He said he now only experiences thoughts of violence towards himself, not to other people, and thinking about his former self makes him “cringe” because of “how selfish and self-centered I was”.

Family of Miss Hogg watching from London groaned when Dunlop said he has had suicidal thoughts as a result of diagnosed post-traumatic stress disorder (PTSD).

On whether he considers himself a risk to the public, he said: “No, I’m more frightened of them than they should be of me – I’m more concerned about people finding out where I am and causing me harm… I don’t want to cause anybody any harm.”

A prison psychologist and an independent psychologist agreed that Dunlop should be released after finding a low risk of violence, increasing to moderate in the community.

Dunlop’s Prison Offender Manager said his ability to cope had improved.

She observed this last year as he navigated his son’s death, then-justice secretary Shabana Mahmood’s intervention to keep him in the prison, and the documenting of his case in ITV drama I Fought the Law.

Dunlop has served five years more than his minimum term for murder.

He was already imprisoned at the time of that sentence and has now been detained for around 28 years.