Today Stuart Hazell was jailed for life for killing Tia Sharp, the 12-year-old schoolgirl who had become the focus of his sexual interest.
This was a case involving many horrendous elements but there was one that stood out in a particularly worrying way.
Hazell, 37, was a man with a violent and scarred background which is nothing unusual in such crimes. But, tellingly, he also had an addiction to images of children being sexually abused. Police discovered hundreds of such pictures on his computer hard drive. He had also visited websites searching under 'illegal incest pics' and 'sex with young children'.
For some time now the NSPCC and other authorities have been concerned about the seemingly unstoppable wave of child abuse images that are flooding the internet. We recently discovered that an astonishing 26million had been confiscated by just five police forces in England and Wales during the last couple of years.
That's an almost unimaginable figure. But if we think in terms of each image being the equivalent of an average camera snap we can start to visualise what we're dealing with.
If you printed out each 6 x 4 inch picture and laid them end to end they would form a hideous 2000 mile trail from London to Cairo and every one would show a real child being abused.
So we have come a long way since 1990 when the Home Office estimated there were only 7,000 hard copies of such images in circulation. As we pass the landmark 20th anniversary of the first website its quite clear that the internet has lit the fuse for an explosive problem that will not erase itself.
A couple of weeks ago a young man was convicted of having one of the biggest hoards of child abuse images ever discovered in the UK. He had been collecting the astonishing haul of eight million pictures for over a decade, since he was 12 years old.
But it's not just the number of images that is causing concern. It's the affect they can have on the men who collect and pass them on. In another unrelated case a court heard that a middle-aged offender caught with abuse pictures had become 'desensitised.' After spending hours every day looking at the online images, which involved children as young as eight being abused, he was now 'unable to differentiate between what was acceptable and what was not.'
The problem has now reached such a pitch that the Child Exploitation and Online Protection Centre has today made tackling the issue one of its major goals. Previous research from the police-led organisation has shown that around three-quarters of convicted child sex offenders used indecent images to stimulate themselves or 'groom' the children they were abusing.
This really underlines just what a vicious cycle we have to break. Children - even babies - suffer horrific sexual assaults so the images can be made and these are then used to provoke more child abuse.
The police are of course doing all they can to prevent the circulation of these pictures with many forces having specialist internet squads. In 2011 they arrested over 2,300 offenders for taking, possessing or distributing child abuse images. The number of convictions has also risen to nearly 1,500 compared to 95 in 1995.
And over the last 17 years the Internet Watch Foundation has also been extremely effective in reducing the amount of child sexual abuse content being hosted on UK websites, slashing it from 18% of the worldwide total to less than 1%. However one of their studies found that 1.5million men and women in Britain had seen or stumbled across child abuse images. These people also saw it as a bigger concern than websites related to terrorism or promoting suicide.
And there is still a continuing flow of court cases involving people who have been caught with or have passed on child abuse images. They include teenagers and pensioners and come from a variety of backgrounds including, policing, social care, nursing, teaching and IT. Some are married with children; others are described as loners. There is no set pattern.
You could argue that as horrendous as the problem is it still doesn't affect the vast majority of the population. But in the hands of the wrong person, someone like Stuart Hazell, these images could well become the catalyst for an even more dreadful crime and that's something that cannot be ignored.
Of course not everyone who looks at indecent pictures of children will commit other offences. But if we use our technical know-how to prevent the circulation of such images we can at least reduce that temptation. Banging home the message that each picture is a crime scene where a child has actually been assaulted and could therefore lead to the viewer being prosecuted could also act as a deterrent. And there has to be treatment for those convicted of taking, possessing or distributing images so they fully understand the gravity of what they've done and do not repeat the offences.
We can't be naïve enough to think this can be solved overnight but we also shouldn't take the attitude that it's too big to deal with.
A dedicated and long term approach is needed to kill off an 'industry' where, sadly, 26million sickening images are just a drop in the ocean.