A 49-year-old engineer has pleaded guilty to thirteen charges of making indecent images of children at Londonderry Crown Court.
Michael Mullan, from Cooleen Park in Derry, admitted committing the offences between 2005 and 2008.
Judge Piers Grant told Mullan that it was "almost inevitable" he would go to jail.
He was released on bail and will be sentenced next month.
An order was also issued for the destruction of Mullan's computer.