The former boss of a Victorian prison is himself behind bars, sentenced to three years and five months in jail on a string of child abuse material charges.
Wayne Harper, the former head of Marngoneet Correctional Centre, made and swapped sexualised images of 5490 different children over a four-year period.
He was caught in August 2019 after selling his home in Geelong, when the new owners of his house discovered two USB sticks full of child exploitation material hidden in a shoe at the top of his wardrobe.
Police then seized his computers and Department of Justice phone, where he had stored thousands of images, as well as a screenshot of a web page showing the username "Mr Tickles".
The father of three swapped the images online many times a day, exchanging his disturbing sexual fantasies about children with four online contacts, one named "El Diablo".
At one point, Harper wrote: "Those little girls want sex just like we do".
"Look how young she is, even at that age it still feels good," he said.
In total, police uncovered 5808 images of child exploitation, as well as 168 videos, showing children as young as two years old.
Many of the images showed adults engaging in sexual acts with children.
But a large proportion of the pictures were taken from the Instagram accounts of young girls showing themselves in their underwear.
Judge Patricia Riddell said his offending was "abhorrent to decent minded members of the community", who should be able to expect a that prison manager would have some concern for victims of crime.
"You have exploited those children", she said.
Harper, 58, pleaded guilty to five charges of possessing, producing and transmitting child abuse material between July 2015 and September 2019.
He is likely to serve his sentence in protective custody.
He'll serve a non-parole period of two years and three months.