I would have thought that actively seeking sites online which portray child abuse indicates ones interest in the subject. By viewing them one is encouraging the image-makers to produce the videos/photos. This is participating in that abuse at second-hand. He apparently viewed these things many many times, using a large number of sites with titles suggesting sexual activity with young people or children. He had written in a notebook the system, ineffectual as it happened, for deleting them from his computer, so he obviously was well aware they were illegal and unacceptable.
All children are indeed innocent. Any deviation (I use that word advisedly) from this stance is paramount to the self-justifying paedophiles who declare 'the children love it' and 'he/she wanted me to do it'.
Some of the things he did were absolutely disgusting and horrifying. Not just 'touching' or 'groping', words which sound almost light-hearted. If one's own child had been attacked in this way, I am sure one would want to commit murder.