Luke Deeley, 26, bludgeoned mum-of-three June Fox-Roberts, 65, in her home in Llantwit Fardre, South Wales, causing her to collapse.
He then dragged her unconscious body into the dining room and placed her on tarpaulin before decapitating her.
Deeley also chopped June’s body up and placed her limbs in separate plastic bags before leaving her worried daughter to discover her mum in a “murder scene of nightmares”.
Haunting footage later showed the art student rocking back and forth in an industrial park.
Deeley, who was obsessed with “Satan and demons”, also appeared to be singing and muttering himself after spending the night in a trailer following the bloodbath.
The footage was released after paranoid schizophrenic Deeley was detained in hospital under the Mental Health Act on Friday.
He previously pleaded guilty to manslaughter by way of diminished responsibility.
Newport Crown Court heard Deeley had been studying illustration at the University of South Wales but left his student accommodation ten days before the attack.
Complaints had been made about him after he threw water over a female student while calling her a “c***”.
On November 21, 2021, Deeley entered June’s house while she was home alone after her daughters went away for the weekend.
Prosecutor John Hipkin KC said: “She was assaulted whilst upright in the hallway and further assaulted whilst on the floor.
“From the hallway of the premises the defendant dragged June Fox-Roberts into the dining room area of the property and placed her in a tarpaulin.
“He proceeded to decapitate and dismember her and placed her limbs into separated bags using an axe recovered at the scene to achieve this.
“He had also brought a chainsaw into the property from an outside shed. The forensic findings are that it was not used in the dismemberment process.”
A post mortem found June had suffered blunt force injuries to her head that appeared to have been sustained while she was still alive.
These included a blow to the forehead that knocked her out and other injuries that indicated “stamping”.
Her body was discovered by her daughter and a neighbour after they grew concerned about not being able to reach her.
Deeley had attempted to clean the bloodied hallway with bleach before he shaved and dyed his hair in a bid to change his appearance.
He then fled the scene and slept in a trailer in a nearby industrial estate.
CCTV footage played to the court showed Deeley talking and singing to himself while wrapped in a blanket after the attack.
He was arrested two days after the killing before he claimed he had been instructed by a “higher power” to kill someone.
Speaking after the sentencing, June’s family said: “On Sunday November 21st, 2021, our world imploded. June Fox-Roberts was taken from us in a horrific way by a complete stranger.
“June was a mother, grandmother and great grandmother and loved spending time with her extended family.
“June was so excited to meet her great granddaughter, born earlier that month but sadly Luke snatched that chance from her.
“June had a huge heart and would welcome anyone with open arms into her home – she was well known for not letting you leave her home or garden without a cuppa or glass of wine and a good natter first.
“And she was generous, if anyone had a problem, she would do anything in her power to help – which makes it so much harder to accept Luke could be so cruel to her for no reason.
“June was not afraid of death, but she wanted to die peacefully with her family around her and Luke stole that right from her and all of us when he took her life years before her natural time.”
4
4