The Australia National Broadband Network contractor was accused of raping the 12-year-old after ambushing her on a pathway in Narara on the Central Coast.
He was wearing a military style ghillie suit when he grabbed the child and pulled her into secluded bushland that he had already scoped previously as an ideal spot for the attack.
He stripped her naked and tied her to a tree before raping her while also taking photographs of the ordeal.
When police swooped on his house they found what was referred to as a "rape kit" including hunting knives, camouflage clothing, cable ties and other items.
The arrest was made as part of a three-month investigation, after officers were able to link the two attacks thanks to detailed description provided by the 12-year-old victim.
"Obviously she is relieved that an offender has been arrested, and it is an obvious comfort to her," Detective Superintendent Linda Howlett said.
"I also want to acknowledge the bravery of the victim. She has been absolutely exceptional with the detail that she has been able to provide the investigation."
Police previously said they believed the man involved in the attacks wore the camouflage suit to carry out a "hunter fantasy".
After several interviews with the two young victims, detectives said the man had been wearing a dark camouflage coloured top and pants with fake leaves attached to it, along with a matching mask, gloves and backpack.
The arrest was made as part of a three-month investigation. Photo / NSW Police
A photo of a person in a similar suit was posted on one of Johnson's family members social media pages, while his own account also featured hunting pictures.
It is believed a lair was used by the man while he allegedly attacked the 12-year-old girl while dressed in a leafy "Ghillie" suit.
Troy Stephen Johnson (pictured) abducted and sexually assaulted two young girls in NSW. Photo / Supplied
The lair was hidden out of sight from a nearby walking path that many students, including the 12-year-old girl, took to get to school.
The hidden lair was littered with rubbish alongside a plastic orange chair, old tyres and a make-shift tent made out of a large draped sheet.
