Grandmother killer Hayden Kidd could be freed within months

A young man who killed his grandmother with a mattock during a cannabis-induced psychosis could be freed from jail within months.

Hayden Leigh Kidd, who bludgeoned his own grandmother to death with a garden tool, arriving at the Victorian Supreme Court on Thursday. Picture: NewsWire / David Crosling

A young man who hacked his grandmother to death with a garden tool while he was in a cannabis-induced psychosis could be released from custody within months.

Hayden Kidd, 22, pleaded guilty to manslaughter after he killed his grandmother Shirley Kidd, 67, with a mattock in the garage of her Darley home where they both lived, believing she was his abusive stepfather.

Describing it as a “horrible case”, Supreme Court justice Michael Croucher on Thursday jailed Hayden for five years with a non-parole period of 2 ½ years after finding his moral culpability was almost non-existent.

Hayden Kidd, 22, pleaded guilty to manslaughter for killing his grandmother Shirley Kidd, 67, with a mattock.

“On the one hand, the killing itself was gruesome and objectively grave,” he said.

“After all, an innocent person was hacked to death in her own home.”

But the judge said Hayden in his “utterly deluded state” had little understanding of what he was doing as he brutally killed his grandmother.

“His mind was so disordered he believed his grandmother was his sadistic stepfather,” he said.

“It’s plain his awareness of what he was doing at the time was severely compromised.”

Hayden was trialled for murder but the jury was discharged without verdict after two psychiatrists found he did not have an intention to kill because of his psychosis.

With time served, he could be released on parole within months.

The court heard Hayden was subject to extreme physical abuse at the hands of his stepfather before he was able to escape and move in with his loving grandparents about 18 months prior to the fatal incident.

Shirley Kidd (left) was killed in her garage in Darley, near Bacchus Marsh. Picture: Supplied

He was unemployed and spent most of his time in his bedroom which was a source of tension between them but was still close with his grandparents, particularly his grandfather.

On the night of May 28, 2022, Hayden’s then seven-year-old cousin, who was staying with the family, was sleeping in a bedroom with Shirley, when Hayden entered the room and picked him up.

The boy later told police Hayden took him to the garage and began opening the door, before he was confronted by Shirley who told him to put him down.

Hayden picked up the mattock — which had been used to weed their garden just days earlier — and struck her in the head with it in front of his young cousin.

The cousin raised the alarm with their grandfather, who was sleeping in a different room, who went into the garage to discover his wife of 43 years lying face down in a pool of blood with the tool lodged in the back of her skull.

Hayden, who appeared pale and was struggling to keep his eyes open, then walked past him and said: “I’m going to sleep well tonight.”

Other family members and a friend were called to the home before Hayden, who appeared drug-affected, was arrested without incident.

The scene was so distressing that one family member began throwing up while they were on the phone to emergency services.

Trace amounts of THC, which is found in cannabis, and an antidepressant were found in Hayden’s system.

He later told psychiatrists his memory of the attack was a blur but believed his cousin was a younger version of himself while his grandmother was his abusive stepfather.

Hayden’s barrister Tim Marsh said it may be a better option for his client to remain in custody as he no longer had family support and had nowhere to stay if released.

“The state is not a parent, the state is not a family, but the state can provide scaffolding support for vulnerable individuals,” he said.
Seated in the dock, Hayden showed little emotion during the sentencing hearing.