An investigation has been launched into how a sheriff's officer managed to keep multiple guns - including one that he used to murder his ex-lover's friend - despite a domestic violence complaint being made against him.

Nightclub bouncer and aspiring actor Warren Browne, 42, drove more than 80km to his former partner Brook Hamilton's home in Kotara South, Newcastle, on Saturday.

He blasted a shotgun round through the front door, yelled to Ms Hamilton and told her he loved her, then turned the gun on himself.

The couple had only been in a relationship for a short time before he began harassing her.

Nightclub bouncer and aspiring actor Warren Browne, 42, drove more than 80km his former partner Brook Hamilton's home in Kotara South, Newcastle, on Saturday

Police are now investigating whether the shotgun and several other guns in his possession should have been confiscated when Ms Hamilton filed a harassment report, according to The Newcastle Times.

Browne, a bald and heavily tattooed aspiring actor from Terrigal, would not stop contacting the woman and became increasingly angry at his rejection.

He blasted a shotgun round through the front door, yelled to Ms Hamilton and told her he loved her, then turned the gun on himself

The woman's mother said Browne would not take no for an answer and so her daughter reported him to the police.

While she didn't want to take out a domestic violence order (ADVO), police policy meant one was taken out regardless of her wishes.

An interim ADVO meant Brown's firearms should have been confiscated.

Lake Macquarie police district commander Superintendent Danny Sullivan told the publication an investigation had been launched.

Browne armed himself with a shotgun and drove 80km from Terrigal to the woman's modest granny flat on a quiet cul-de-sac.

When he arrived he blasted a round through the glass doors of a small flat attached the rented home on Blackbutt Parade.

Anthony Beck, a Williamtown RAAF Base employee, was standing on the other side of the glass.

He had only just met the woman, aged in her 20s.

The 42-year-old father - who was engaged to be married - was shot in the head and killed.

Browne was a nightclub bouncer for 17 years but wanted to be an actor. He became enraged when his former partner continued to reject his unwanted advances

Nightclub bouncer Warren Browne, 42, drove 80km to blast a shotgun through the door of a woman in her 20s who had a brief affair with him before dumping him

The woman immediately fled, jumped out a back window and hid under a neighbour's house as they called Triple-0.

A witness heard the heavy-set killer say 'I love you' and a woman's name before he turned the gun on himself.

When police arrived at the scene shortly after 5pm they found Browne's body lying outside and Beck's body lying inside the shattered glass door.

Shocked neighbours said they had heard three gunshot blasts.

Neighbour Ian Robertson said he had just returned from grocery shopping when he heard the shots and called the police.

'I heard bang, bang, bang and at first thought it was the gas heater going off,' he told the Newcastle Herald.

'I ducked inside and heard a rattle, crash and bang inside the house and then heard her scream.

A picture from William Browne's advertising page on Starnow. The aspiring actor murdered a father who was engaged to be married before turning the gun on himself

Blackbutt Parade, Kotara South, where the shooting shocked the neighbourhood on Saturday

'He came out and he said 'I love you' and a name and then I heard a shot. I knew it was over.'

Another neighbour said he saw the gunman and described him as calm, not aggro or boisterous.

Although the woman had reported Browne's harassment to police they had not taken out an apprehended domestic violence order (ADVO) against him.

Browne had been an extra on the TV show Rake and a hardware commercial in 2016.

On his Starnow talent directory page he wrote that he had experience in self-defence videos and student films.

'I am very charismatic and energetic person. I have had various parts in horror mazes and I interact with other actors very well,' he wrote.

The coroner will investigate.

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