Joan Hoggett death: Police chief speaks of 'absolute randomness' of attack on shopworker Joan Hoggett who was stabbed to death by Ethan Mountain

A police chief says he was left shocked by the "absolute randomness" of killer Ethan Mountain's savage stab attack on shopworker Joan Hoggett.

Mountain stabbed 62-year-old Joan multiple times in an unprovoked and sustained attack as she stacked shelves at the One Stop shop on Sea Road on the evening of September 5 last year.

Joan Hoggett's daughter, Michelle Young, and Joan's son, Robert Young (right) are joined by other family members at Newcastle Crown Court.

Joan Hoggett's daughter, Michelle Young, and Joan's son, Robert Young (right) are joined by other family members at Newcastle Crown Court.

The 19-year-old admitted manslaughter with diminished responsibility.

He denied murdering the grandmother – claiming he “was not in the right frame of mind” at the time of the offence - and a judge ordered the jury to find Mountain, 19, not guilty of murder on the grounds that his mental responsibility for the killing was diminished.

The court was told Mountain had been admitted to a psychiatric hospital in 2017 and treated with anti-psychotic medication.

READ MORE: Prosecutors explain why Ethan Mountain was found not guilty of murder

Ethan Mountain will face sentence for the manslaughter of Joan Hoggett after being found not guilty of murder.

Ethan Mountain will face sentence for the manslaughter of Joan Hoggett after being found not guilty of murder.

Superintendent Paul Milner, of Northumbria Police, paid tribute to the victim’s family following the trial.

He said: "This was a horrific incident and what further shocked me and the community was the absolute randomness of the attack.

WATCH: Family of Joan Hoggett make plea over knife crime as they urge those with mental health issues to seek support

"Generally, with these types of crimes – which are very rare in the North East – the perpetrators are known to the victims. However, there was no link whatsoever between Ethan Mountain and Joan Hoggett, who went to work fully expecting to return home to her loved ones that night.

Inside the One Stop shop in Sea Road, Fulwell, where Ethan Mountain stabbed Joan Hoggett to death

Inside the One Stop shop in Sea Road, Fulwell, where Ethan Mountain stabbed Joan Hoggett to death

"I would like to thank Joan’s family for the incredible bravery they have shown over the last six months, as well as the team of detectives for their dedication and hard work on this case.

Listen to 999 call made to police by friend of Ethan Mountain after he stabbed Joan Hoggett to death

"Following Joan’s death, the community of Sunderland came together to pay their respects and show unity in response of this devastating incident. I would like to thank everybody, especially those who live in Fulwell, for their cooperation and assistance throughout this investigation."

The court was told how Mountain, carrying a rucksack containing knives, left his home in Heaton Gardens, South Shields, and walked to East Boldon Metro station shortly before boarding a train to Seaburn at around 10pm on the night of the killing.

A sheath found in Roker Park with Ethan Mountain's DNA on it

A sheath found in Roker Park with Ethan Mountain's DNA on it

He was seen walking down Sea Road before stopping outside the shop. He then pulled on a mask and entered before attacking Joan, who suffered fatal injuries.

Leaving his bag at the scene, Mountain was caught on CCTV running away from the store. He went on to discard the knife, a jacket he was wearing and his mobile phone as he fled.

Shortly after, the teenager turned up at a friend’s house, who called the police and took Mountain to Whitburn Park, where he was arrested on suspicion of murder.

Over the next few days, police carried out a large-scale investigation which saw officers close off Roker Park, where a knife sheath was found which contained traces of Mountain’s DNA.

A team of divers also searched a pond inside the park for Mountain’s mobile phone, which was never found. The jacket he had worn during the attack was also found discarded in the garden of a property in Calderbourne Avenue.

CCTV footage shows Ethan Mountain before and after he stabbed Joan Hoggett to death

Popular great-grandmother Joan Hoggett was killed by Ethan Mountain at the One Stop shop where she worked.

Popular great-grandmother Joan Hoggett was killed by Ethan Mountain at the One Stop shop where she worked.

After being charged with murder, Mountain responded: “It was not me; I was not in the right frame of mind.”

Northumbria Police said Mountain refused to cooperate in interview but later admitted manslaughter on the grounds of diminished responsibility during a hearing at Newcastle Crown Court in January.

Today, the charge of murder against Mountain was dismissed by a judge based on the grounds that the defendant’s mental responsibility for the killing was diminished.

He is due to be sentenced on Friday, March 22.

A holdall belonging to Ethan Mountain which was recovered by police.

A holdall belonging to Ethan Mountain which was recovered by police.