NT Police Senior Sergeant Sandi-lee Mellon pleads guilty to assault of Neil Mellon’s mistress and her former best friend

A Northern Territory cop who uncovered her husband’s two-year-long affair with her best friend in his arrest paperwork has told the court she ‘snapped’ after her life ‘completely caved in’.

Former Miss Universe Australia contestant Narelle Jose and NT Police Senior Sergeant Sandi Mellon.

A decorated Northern Territory cop who ‘snapped’ after her husband’s arrest and attacked his mistress in her own home has escaped conviction.

Former Senior Sergeant Sandi-lee Mellon told the Darwin Local Court on Thursday that on the morning of August 25, 2022 her life “completely caved in”.

Mellon pleaded guilty to assaulting her best friend the day after her husband and fellow senior police officer Neil Mellon was arrested on serious conspiracy charges in relation to a fatal helicopter crash that killed a reality television star.

Defence lawyer Megan Donahoe said the 46-year-old was able to access her husband’s disciplinary paperwork, which revealed a two-year-long affair with her then best friend, Narelle Jose.

“It was a level of deception that was hard to process,” Ms Donahoe said.

She said Mellon was “utterly distraught and out of her mind”, and was hospitalised following a suicide attempt that night.

Northern Territory Water Police officer in charge Senior Sergeant Sandi Mellon (left) with Neil Mellon . Picture: Supplied

Ms Austin heard that the next day a “highly emotional” Mellon barged into her friend’s home with her son and son-in-law to confront Ms Jose about the affair.

CCTV captured the serving police officer yelling out: “You manipulative c—t, you f—king psycho. How dare you”.

The two young men had to hold back Mellon after she attempted to punch her former-friend.

The court heard her right fist made “glancing” contact with Ms Jose’s shoulder before Mellon was pulled back.

As she left, Mellon yelled from the backyard: “I’m going to f—king kill you Narelle.”

“Don’t you worry, when you least f—king expect it. You c—t, I’ll get you,” she screamed out.

Former Senior Sergeant Sandi-lee Mellon leaving Darwin Local Court after pleading guilty to assaulting her best friend and husband's mistress in August 2022. Picture: Zizi Averill

Prosecutor Tamara Grealy said the attack was “brazen” and targeted her victim in “a place where she is entitled to feel safe”.

Ms Grealy said even with the emotional circumstances it was not appropriate for anyone — let alone a serving police officer — to engage in violence and threats.

In a victim impact statement, Ms Jose said she was still impacted by the terror of the incident and had taken out a personal violence order against Mellon.

On Thursday, Mellon pleaded guilty to a single charge of common assault, after allegations of unlawfully entering the home, trespass, assault, making a threat to kill and disorderly behaviour were withdrawn.

Ms Donahoe said her client regretted going to her former-best friend’s home, and believed the criminal charges were a major factor in her dismissal from the police force after 28 years of service.

“She’s lost her career, her livelihood, she lost her marriage, she lost her best friend, she lost her privacy,” she said.

“Her trauma has been used as gossip fodder.”

Former NT Water Police Officer in Charge Senior Sergeant Sandi Mellon.

Mr Mellon — who was not charged in relation to the assault of Ms Jose — was arrested and charged with destroying evidence, obtaining benefit by deception and leaking sensitive police secrets following the helicopter crash that killed Netflix star, Outback Wrangler star Chris ‘Willow’ Wilson.

A former NT Police acting senior sergeant, Mr Mellon recently spent three months in prison after pleading guilty for his role in the alleged crash cover-up.

Ms Donahoe said Ms Mellon was already on stress leave at the time of the assault, and had since been diagnosed with post traumatic stress disorder and depression.

Defence lawyer Megan Donahoe leaving Darwin Local Court. Picture: Zizi Averill

While trying to avoid “victim blaming”, Ms Austin acknowledged Mellon had suffered “two betrayals” by the people closest to her.

“(She) had every right to feel aggrieved, and terribly betrayed and upset,” she said.

“But the issue is ‘did Ms Mellon cross the line?’ — and she did.

“The web and the loop that Ms Mellon was subject to was so out of her control that I do think she snapped.

“Her actions on the day were so out of character … she crossed the line personally, morally, professionally”

Ms Austin made a non-conviction order for the assault and imposed a nine-month community corrections order, which included a provision that she could not contact Ms Jose.

Originally published as NT Police Senior Sergeant Sandi-lee Mellon pleads guilty to assault of Neil Mellon’s mistress and her former best friend