The officer noted Parsons had made internet searches for illicit material including one for a "10-year-old girl and 20-year-old man", and another referring to schoolgirls.
When police further examined the device, they found a 47-second video of child sex abuse.
Parsons subsequently pleaded guilty to possessing an objectionable publication.
Judge Michael Crosbie called the offending "vile and degrading" and reminded the defendant there was a real victim at its heart.
"Your possession of this video amounts to sexual exploitation of a child - a child of incredibly young and tender years," he said.
Parsons, the court heard, was struggling to answer questions about sexual arousal.
In a pre-sentence interview, he strongly disputed being attracted to children and claimed the downloading of the video was an accident.
In 1995, the defendant, who was then 18, was jailed for 11 years for the rape of the 12-year-old girl.
Since his release from prison, his wayward behaviour had continued.
While living at a residential facility, Parsons invited a prostitute to the address - a breach of the rules.
And in December 2015, Parsons deviated from an approved route to work to approach a 15-year-old girl wearing a school uniform.
He did so again in May 2016, giving her a note with his cellphone number, asking her to buy underwear and other items.
In imposing the ESO in 2017, Justice Gerald Nation noted Parsons' gender issues had reportedly been the driver for much of his offending.
"He wants to be living as a woman ... in a relationship with a woman who accepts him as transgender," the court heard.
Parsons was jailed for nine months. His ESO will be suspended while he serves the sentence.
