how long? as long as it attracts and maintains advertising revenue... and people talk about it.
I sometimes think the non-stop media focus - and audience attention - on children such as jonBenet is a weirdo form of voyeurism/virtual pedophilia.
First it was torture-the parents by media without solid evidence, vaguely reminiscent of the dingo-took-my-baby saga in Australia. For some reason a lot of people wanted the mother to be guilty - when eventually she was found innocent but not before years of harrowing trial-by-media and uninformed public opinion - perverse.