Johnathan Marcus Horton pleaded guilty to making a child amenable to sexual activity

An Adelaide chef who believed he was talking to a grandmother advertising her five-year-old grandchild for sexual activity gave a crazy reason to police for doing so.

A predator wrote “graphic” descriptions to an undercover officer pretending to be a grandmother of what he would do to a five-year-old child.

However, Johnathan Marcus Horton, 30, said he sent the messages as a ruse to uncover the woman’s identity so he could inflict harm on her.

During sentencing submissions, the District Court heard Horton was talking with an undercover officer posing as a grandmother advertising her five-year-old grandchild for sexual activity.

Hannah Bird, for the prosecution, told the court they didn’t accept Horton’s explanation as to why he engaged in the offending.

Ms Bird pushed for immediate jail, saying Horton’s messages over a four-month period showed he instigated involvement in the abuse of the fictional child.

Johnathan Horton pleaded guilty to making a child amenable to sexual activity. Photo: File

“As the conversations continued, the defendant repeatedly wrote graphic descriptions of what he would do to that child,” she said.

The court heard Horton also asked to see a photo of the child and a psychologist found him to have a pedophilic disorder.

“On the day of this apprehension and arrest was the final discussion about the hotel room,” Ms Bird said.

“Had he actually been speaking to a real person, there may have been a real opportunity to physically act on the abhorrent desires that he wrote about in relation to interactions with a real child.”

Horton, of Munno Para West, pleaded guilty to making a child amenable to sexual activity.

Nick Vadasz, for Horton, admitted his client was getting sexual gratification from the messages but said there were mixed motives for his offending.

Mr Vadasz said Horton agreed to meet with them as a ruse to inflict violence on the grandmother, intending to kill her.

“Another time he said ‘let’s meet at a playground’, so he wasn’t entirely averse to the meeting but he was resisting a meeting at a hotel and eventually the undercover operative agreed to pay for the hotel herself,” he said.

Judge Kris Handshin said he wasn’t sure he could accept Horton’s explanation, noting a message where he said: “I really can’t wait to meet you both. It’s going to be an amazing night”.

The court heard Horton was a chef and had been employed for most of his life.

Judge Kris Handshin said he’d review the materials and decide whether he could accept Horton’s explanation.

The charge was adjourned until next week.