Horrific way mother murdered her male friend is revealed as she's thrown behind bars for 18 years over the 'senseless' attack

A drug addicted mother who brutally stabbed her friend 18 times at a Sydney housing commission estate has been jailed.

Sharee Turnbull attacked Jack Mulligan with a knife behind a garage at the Johanna O’Dea Court housing complex in Camperdown in September 2019.

The 41-year-old was on parole at the time of the murder where she approached her 25-year-old victim from behind, leaving Mr Mulligan riddled with stab wounds.

Sharee Turnbull stabbed Jack Mulligan 18 times at a Sydney housing complex

The mother-of-seven had no explanation for the horrific murder and she was sentenced to 18 years jail, with a non-parole period of 12 years six and months.

Supreme Court Judge Peter Hamill said Mr Mulligan's life was 'senselessly, tragically and inexplicably cut short', as reported by The Daily Telegraph.

Judge Hamill said evidence showed the pair were friends and may have been looking for drugs together on the night Mr Mulligan was murdered.

The 41-year-old had no explanation for the murder of Mr Mulligan and received 18 years in jail

He could not say whether Turnbull was trying to kill Mr Mulligan, but Judge Hamill said the ferocity of Turnbull's attack showed intent to hurt her victim.

'This is because of the senselessness of the killing and because of the number of stab wounds,' he said.

'The conclusion that, at the relevant time, Ms Turnbull intended to inflict serious injury upon Mr Mulligan is inevitable.'

In previous hearings Turnbull has accepted responsibility for the crime and shown remorse for her actions.

She will remain behind bars until at least 2032. 

Mr Mulligan’s aunt Carolyn Holder said though nothing could bring back her nephew, Turnbull's sentence was appropriate. 

'I honestly hope she is able to rehabilitate and able to do something positive for her family,' Ms Holder said.

Turnbull previously told the court she had been using methamphetamine daily and couldn't remember the attack but felt 'guilt, a lot of shame pain' for what she'd done. 

Turnbull (pictured being arrested by police) has accepted responsibility for the crime and expressed remorse

She also spoke of her traumatic childhood and early adult life replete with domestic violence, drug abuse and poor role models and how losing her son moments after giving birth aged 18 had led to an escalation in her drug use.

'I know what the pain is like to lose a child,' Turnbull told Mr Mulligan's mother from the witness box, adding she would bring him back if she could.

'I regret everything.

'I can't live with the pain, but it's something I have to face because I'm responsible.'

Turnbull had used illicit substances on multiple occasions since entering custody in September 2019 and also used ice the day she was released on parole in May 2019 for stabbing a man in the chest in January 2018.

But Turnbull testified had been clean for three months and began a rehabilitation program in October after 'having a reality check with where I was, everything I've done and everything I've lost'.

Turnbull is escorted to a prison van outside the Supreme Court in Sydney on December 7

Turnbull's older sister, Karla, told the court how they grew up with an alcoholic mother whose addiction escalated after Turnbull's maternal aunt was murdered by a domestic partner.

Both sisters recalled witnessing a relative hold a knife to their mother's throat and walking the streets at night out of fear of going home.

Karla Turnbull said her sister had been getting better in her mid-teens but the death of her son changed her forever.

'When she lost her son, I lost my sister,' she said.