A mentally unwell Sydney man who became fixated on Jackie ‘O’ Henderson has been jailed after bombarding the radio star with an extraordinary number of messages and later turning up outside her home.

David Gourlay, 38, convinced himself that he and the KIIS FM host were in a romantic relationship, despite never having met her.

Over a five-month period, he sent her up to 2000 Instagram direct messages, many arriving in rapid succession and referencing private details about her life.

In the delusional narrative he constructed, Gourlay even claimed the pair shared a child.

Jackie O, whose full name is Jacqueline Henderson, never replied to any of the communications.

On July 3, Gourlay sent a message declaring, ‘I am not giving up on us.’

A mentally unwell Sydney man who became fixated on Jackie ‘O’ Henderson (pictured) has been jailed after bombarding the radio star with an extraordinary number of messages and later turning up outside her home

Some of the messages were described as graphic and sexual, leaving the radio identity increasingly distressed.

Matters escalated further when Gourlay arranged for flowers to be delivered to her home, incorrectly addressed to ‘Jackie Anderson.’

Police later located him sitting on a bench outside her residence in Sydney’s eastern suburbs and detained him for a mental health evaluation.

Sydney’s Downing Centre Local Court heard today that Gourlay has schizoaffective disorder with bipolar features, and that his belief he was in a relationship with Henderson had stemmed from severe delusions.

His lawyer, Trudie Cameron, told the court her client had been struggling significantly and had not been taking his prescribed medication.

He had reported hallucinations and paranoia in the period leading up to the barrage of messages.

An expert report linked his conduct directly to his mental health condition, with the court hearing that the offending occurred entirely within the context of his delusion.

Cameron said that when Gourlay is stabilised on medication, he functions well in the community.

David Gourlay, 38, (pictured) convinced himself that he and the KIIS FM host were in a romantic relationship, despite never having met her

She argued for him to remain in the community to serve his sentence, emphasising his remorse and his understanding of the impact his behaviour would have had on Henderson.

The prosecution, however, submitted that the 38-year-old should be imprisoned, describing the sexualised messages as ‘abhorrent’ and stressing the need to send a clear signal of deterrence.

Deputy Chief Magistrate Theo Tsavdaridis said the content of the messages was extremely concerning and that Henderson’s fear for her family’s safety was entirely justified when Gourlay appeared near her home.

He also noted that Gourlay already had a lengthy criminal history and had been serving two community-based orders at the time of the offending.

Gourlay was sentenced to 16 months in prison, with a non-parole period of eight months.

Taking into account time already served, he will be eligible for parole in March.

A five-year apprehended violence order has also been put in place, preventing him from contacting Henderson in any way except through a lawyer.

The order, which expires in 2030, bars him from assaulting, threatening, stalking or harassing the radio presenter or anyone with whom she has a domestic relationship.

Over a five-month period, he sent her up to 2000 Instagram direct messages

Henderson has previously spoken about having a stalker, though she said they did not live in the same state as her.

In 2023, she spoke with co-host Kyle Sandilands about Sophie Monk’s run-in with an allegedly ‘catfished’ man who showed up to her house.

The shock jock, 53, jokingly asked Henderson why she didn’t have any stalkers, to which the radio host replied: ‘Mine don’t live here thankfully.’

When Sandilands pushed for more information, she added: ‘They’re in Australia but I’m not going to say [where]. No one has turned up to my house thank god.’

He then joked Henderson moves around too much for any stalker to narrow down her location.