A Melbourne IT specialist accused of stalking a woman across multiple states after she called off their secret affair will remain behind bars after unexpectedly withdrawing his application for bail.

Karl Lawrence Mentzer, 39, was scheduled to continue his application for bail on Monday afternoon – but instead the court heard he had abandoned his bid for freedom.

Criminal barrister Amelia Beech, for Mentzer, told the court that she had received instructions to withdraw the application moments before the matter was due to be called.

No reason was given for why Mentzer withdrew his application, after the court was told the alleged victim was ‘terrified’ of him.

Mentzer will now remain on remand in Ravenhall Correctional Centre, having previously appeared via video link from the notorious Melbourne Assessment Prison. 

Mentzer allegedly unleashed a stalking campaign against a woman he had been having an affair with before she ended the relationship in January.

The Melbourne Magistrates’ Court last week heard accusations that Mentzer pursued the Sydney woman between January 1 and May 9.

Mentzer – charged with stalking, installing and using an optical device, and using a carriage service to harass – met the woman through their overlapping professions.

Karl Lawrence Mentzer, 39, was charged with stalking

Mentzer allegedly installed a spy camera in a hallway at the QT Melbourne hotel

Melbourne Family Violence Unit Senior Constable Jason Randle detailed the allegations of Mentzer’s alleged offending to the court.

He said Mentzer and the woman had been in a relationship between July 2024 and January this year which they were ‘keeping a secret’ because ‘they both had partners’.

Mentzer flew to Sydney in January and allegedly went to a dog park near the woman’s house ‘where he knew she walked her dog and attempted to see her’, the court was told.

In February, the woman had a pre-planned trip to Tasmania, which the court heard ‘Mentzer knew about’.

She arrived at the Tasmanian airport to find Mentzer ‘waiting in the arrival lounge for her’.

‘I will ruin you, I will burn your life down,’ Mentzer allegedly said after approaching the woman at the airport.

Mentzer also allegedly sent a drone up to keep the woman ‘under surveillance’ while she was in Tasmania.

On March 20, the woman spotted Mentzer allegedly taking photos of her as she entered a building in Melbourne.

Mentzer was remanded in custody after he withdrew his bail application moments before the hearing on Monday afternoon

On April 3, the court heard that Mentzer travelled to Sydney again where he allegedly took a photo of the woman’s husband while he was in a park near their home.

Mentzer then allegedly sent the photo to the woman.

Senior Constable Randle claimed that Mentzer was ‘intimidating the victim and showing her that he was near her house’ and her ‘husband was under surveillance’.

He went on to say that the woman had a pre-booked flight to Melbourne on April 15, which Mentzer was allegedly aware of.

The woman told Mentzer she ‘did not want to see him’, but it is alleged that he was ‘waiting for her’ at the airport again.

The woman allegedly had an hour-long phone call with Mentzer on May 3 in which she pleaded with him to leave her alone.

The woman told Mentzer she ‘feared him and his escalating behaviour’ and ‘did not wish to speak to him again’.

Yet Mentzer allegedly continued to barrage her with messages begging to see her.

‘I feel it is safer if there is space between and distance between us and to break the cycle of hurt,’ she responded.

The court heard that Mentzer went on to send the woman messages day and night on May 7.

‘I’ve been in meetings, I’m quite swamped today and I feel quite threatened and scared please stop messaging [and] audio-noting me,’ the woman texted Mentzer.

Later in the evening, the woman discovered Mentzer’s alleged attempt to be put in the room next to hers when she checked into the QT Melbourne hotel.

The hotel manager said Mentzer had allegedly ‘requested’ their rooms be side by side.

Staff escorted the woman to a different room on a different floor, the court heard.

Senior Constable Randle alleged that Mentzer installed a spy camera facing into the hotel hallway from his room in an ‘attempt to capture footage of the victim’.

The woman met a friend at Holy Grail bar on Chapel Street in Windsor (above) for a drink on the evening of May 7

The woman was not aware of the camera, but police allege they found footage of the hotel hallway on Mentzer’s phone.

Mentzer also allegedly barraged the woman with eight phone calls, 31 audio notes and 30 text messages ‘throughout the night’.

It is also alleged that investigators discovered photos of a police officer at the Melbourne East police station ‘writing notes’ and the QT hotel manager on Mentzer’s phone.

The woman met a friend at Holy Grail bar on Chapel Street in Windsor for a drink on the evening of May 7.

The two women took a photograph in the photo booth, which the friend later posted to Instagram.

Mentzer allegedly called the woman frequently while she was at the bar and this was ‘observed’ by the friend.

The court heard that, the following day, the woman spotted Mentzer outside her Melbourne CBD office building just after midday and unsuccessfully tried to enter without him noticing her. 

Mentzer has been remanded in Ravenhall Correctional Centre (above)

She managed to make it into a lift, the court heard, but Mentzer allegedly put his hand in the doors to stop them from closing.

Mentzer allegedly yelled at the woman accusing her of ‘financially crippling’ him and that he was ‘meeting lawyers and you won’t hear the last of me’.

Senior Constable Randle told the court that the woman was ‘cowering in the back of the lift’ with her ‘hands up, terrified’ during Mentzer’s alleged tirade.

The woman texted Mentzer soon after he allegedly left her in the lift: ‘I am terrified of you.’

The woman then reported Mentzer to police, who said she appeared ‘visibly shaken’.

She later shared the Holy Grail image her friend had posted on Instagram, but this allegedly caused more problems.

The court heard the friend went to Jungle Boy bar in Windsor later that night only to be told by the bartender that a ‘male was frantically looking for her’. She allegedly showed a photo of Mentzer to the bartender, who confirmed that he was the man looking for her.

The bartender alleged that Mentzer had shown her an Instagram photo of the woman and her friend, and that he had been ‘frantically searching for the girls’ around different Chapel Street venues.

It is alleged that Mentzer concocted a story saying the ‘girls’ phones had died’ and they were ‘really drunk’ and he was ‘worried about them’.

Victoria Police launched an urgent investigation and Mentzer was arrested on May 9.

The woman’s friend went to Jungle Boy bar in Windsor (above) and got a shock when the bartender told her that a ‘male was frantically looking for her’, the court heard

Investigators seized Mentzer’s phone and allegedly discovered he had hired a private investigator to ‘conduct surveillance’ on the woman.

Mentzer, who purported to be the woman’s ‘current partner’, sent the private eye the alleged victim’s address, vehicle information and her photos, the court heard.

The court heard the private eye conducted ‘static surveillance’ at the woman’s Sydney home on May 2.

It is alleged the private eye, who had no idea the woman was not Mentzer’s partner, also took video of the woman’s husband while at the Sydney address.

Senior Constable Randle said the private investigator had been in contact and had provided key evidence to police.

Police also allegedly found instructions and receipts for spy cameras, secretly recorded vision of the woman and her husband, and search results for the Chapel Street bar.

Senior Constable Randle previously expressed concern to the court that Mentzer was a danger to the alleged victim.

‘The contents of the phone show the accused is obsessed with the victim and he’s engaging in a pattern of behaviour to locate her,’ Senior Constable Randle told the court.

‘Police are extremely concerned about his behaviour. Whilst there are no definitive means of predicting family violence homicide, the majority of lethal family violence incidents are shown to have previously had one or more of these risk factors [allegedly displayed by Mentzer] identified.

Senior Constable Randle also said Mentzer is ‘an unacceptable risk of imminently engaging in offending that severely jeopardises the safety and welfare of the victim’.

‘The victim is terrified of the accused and his escalating behaviour which has stemmed from her attempting to end the relationship with him,’ he said.

Magistrate Peter Reardon remanded Mentzer in custody to next face court on June  5.