A former teacher at a prestigious Perth boy's school has been found guilty of possessing more than 3000 images of child pornography.
Jeffery Jay McKinnell had been on trial for the past week in the District Court accused of downloading the material, which was found on his home computer in May 2016, when he was a teacher at Guildford Grammar.
He was sacked after he was charged.
McKinnell argued he had unknowingly downloaded the images of mainly girls while he was trying to access adult pornography and he had not intended to possess "any kiddy porn" or "illegal stuff".
The court heard McKinnell told police if he downloaded anything he thought may have been children, he would put it into a file called "spec" which he would go through later and delete.
However prosecutors argued McKinnell was not being "completely truthful or accurate" when he said that, claiming a computer expert could find only three occasions in two years where files were deleted.
The jury deliberated for about two hours before finding him guilty.
He has been released on bail until he is sentenced in April.