Television loves to stare, particularly when something goes wrong.

If there's a murder or an accident, in it goes: pushing and shoving to the front and leaning across the police lines, gawping and passing on every bit of information, all the gruesome gossip. It's even worse in these days of the 24-hour news channels. Everything must feed the monster of the scrolling headline at the bottom of the TV screen.

Which raises a few questions about Soham: A Parents' Tale (STV, Friday, 9pm), a documentary about the parents of Holly Wells, one of the victims of Soham murderer Ian Huntley. In the programme, Nicola and Kevin Wells talked about how they were affected and changed by what happened to Holly and her friend Jessica Chapman, and their subsequent work with bereavement charities, but the programme never felt entirely comfortable. It had the Wells's permission, but here was television doing it all over again: gawping. And the reason we need to be careful about that is the more we make television programmes about murder – however well-meaning – the more we give terrible crimes the dark allure of publicity.

Lionel Shriver, the author of We Need To Talk About Kevin, the novel about a boy who murders his schoolmates, said something along the same lines when she spoke to The Herald recently. "Murderers want people talking about them," she said. "They want people poring over their history and worrying about what drove them to this." If we make programmes about crime, to some extent we give criminals what they want.

This isn't an argument for a ban on programmes about murder but it is a reminder that we have to be careful about them and ask: what is the purpose of this? What is it for? At some point, someone should have gently asked Nicola and Kevin Wells that question – why do they want to talk publicly about this 10 years on? – but nobody did, which means we don't really know why the programme was made.

It was certainly made sensitively, without dwelling on any of the details of the crime, and it was also terribly moving at times, particularly when Nicola looked through the box where she keeps her daughter's possessions: dancing shoes, old report cards, drawings, the ephemera of a 10-year-old girl. "If I want to reflect, I can come in here," she said. And that was hard to contemplate: a person reduced to objects.

On the other hand, there were, even during the worst days, more positive consequences for both Nicola and Kevin, such as the way the community of Soham came out to help when the girls went missing, and the fact that police procedure has been reformed. Both parents also said they would not be brought down by what Huntley did, they would not go under.

However, not even all of those positives were enough to entirely clear the feeling of unease around this documentary. We certainly didn't learn anything new about the Soham investigation; all we saw was Holly's mother and father up close. So what was this programme? Why is it here? And even more disturbingly: why am I watching it? Why are we all still staring?