By PETER CALDER
Murders involving the rich and famous are always mysterious and fascinating. It's part of the mystical allure of their assumed nobility. We cannot bear the thought that their deaths - even their violent murders - might make them just like the rest of us.
Thus the enduring mystery surrounding the deaths of Marilyn Monroe, say, or JFK. When they fall to Earth, it tends to confirm their superhuman status, rather than proving their simple humanity.
So it's natural to approach the documentary about the OJ Simpson case (TV One tonight, 8.30) with more than the usual degree of scepticism and not just because the title, OJ Simpson - The Untold Story, employs the language of supermarket tabloids.
But the provenance of the 75-minute film - it was commissioned and screened by the BBC - entitles it to at least a respectful attention.
The detailed review of the sensational murder spends much of its first half-hour building the case against the former football star who was acquitted in a criminal trial and later lost a civil case brought by the victims' families.
We are reminded of his freeway drive, beamed live worldwide by news crews in helicopters, a scene so bizarre that it at times seemed staged for the cameras.
If we do not conclude, as we concluded then, that this futile flight was at least suggestive of his crazed guilt, we do when we revisit the forensic evidence - the mixtures of blood in his car, the blood-spattered glove and socks found at his house, the history of domestic violence.
But then the documentary shifts, putting not Simpson, but the case against him, under the microscope. And by the time it finishes it has planted so many reasonable doubts about Simpson's guilt that we may feel irrational to ignore them.
A documentary is not a legal case or even the beginning of one. Without the astringent effect of cross-examination, it can never be more than suggestive.
More than once we may wonder why the people who inform this documentary did not contact Simpson's highly paid lawyers when their testimony might have made a difference, and that's a question left glaringly unanswered.
But even if it leaves at least as many questions as answers in its wake (and there is no reason it should need to do more) this film is powerfully persuasive.
The prime witness for the prosecution of the prosecution, a Los Angeles private eye by the name of William Dear, does not seek to introduce what lawyers call evidence-in-chief. The whole programme is a cross-examination. Experts on both sides of the Atlantic lament the obvious (maybe careless, maybe malicious) contamination of evidence.
Dear and others wonder at the absence of evidence that one might have expected to find if Simpson were the killer, such as bruises on his body corresponding to the bruises on the knuckles of a violently struggling Ronald Goldman.
More chilling are some of the failures of the Los Angeles Police Department, the force which harboured the racist thug Mark Fuhrman who repeatedly sought Fifth Amendment protection when asked about his propensity for tampering with evidence.
The cops "eliminated very quickly" a suspect against whom the documentary builds a powerfully suggestive case. (Let's not name him here since the film deserves to preserve its dramatic surprise).
And late in the programme a whole new line of inquiry opens up - and another suspect is introduced.
Not all the possibilities suggested can co-exist and it's fair to say that much of what the film contains is speculative, at times even fanciful.
But so, as we see after watching it, is much - too much, perhaps - of the case against Orenthal James Simpson.