A paint salesman who grabbed a six-year-old girl and threatened to violently rape a teenager during failed kidnappings in Sydney's north has pleaded guilty to the offences.
The Sydney father was arrested in July last year at his Castle Hill house in Sydney's northwest and charged with kidnapping, child abduction and weapon offences relating to two incidents.
He grabbed a 14-year-old girl by the throat and threatened her with a Stanley knife on a footbridge at Westleigh, also in Sydney's northwest, in April 2012.
"If you say anything or do anything I will f*** you really bad," his victim accused him of saying.
She wet herself in fear, but broke free and ran home to raise the alarm.
Hanson also tried to snatch a six-year-old girl from her babysitter at netball courts in South Turramurra in February 2012.
A woman who was waiting to meet friends at the courts noticed a man in a car slowly following the girl as she rode her scooter, court documents state.
A short time later she heard a "short, young, piercing, scared scream" from behind a toilet block where she allegedly saw the man using both arms to hold the girl, whose head could be seen over his shoulder.
"Shhh, be quiet," the woman heard the man say to the girl.
The woman chased him into bush before he disappeared.
Three days before his arrest, detectives matched DNA evidence found on the shirts of both victims to Hanson's DNA profile via a sample of his they obtained covertly.
The court documents say police "believe the accused is a serial predator who, if not located, would commit further offences".
He was later charged with three counts of possessing or disseminating child pornography, after police seized a number of items from his home including a personal computer.
Hanson also pleaded guilty to those charges on Thursday.
He appeared in court via audio-visual link and did not express emotion when his lawyer Shaun Titmarsh entered the guilty pleas on his behalf.
His matter will come before Parramatta District Court on April 5 for sentence.