THERE are many questions that go unanswered in The OJ Simpson Story (World, 9.30pm). The most obvious is, if he didn't do it, who did? Was it the mob? A drug deal gone wrong? Elvis Presley? This is not a film of Oliver Stone-type conspiracy theories. It's not much of a film at all, just the sketchiest linear drawing of the bare facts, from OJ as a child to OJ as a football star, OJ as a minor film celebrity (security guard in The Towering Inferno and dunderhead policeman in Naked Gun ) and OJ as a murder suspect. It is also a medium-budget drama, hastily cobbled together and designed to cash in on Simpson's second bout of fame, first as an American footballer, who no-one outside America had heard of, then as the world's most famous innocent man. On television in the US, Simpson will be putting forward his own version of events on NBC's Dateline, which airs at 9pm West Coast Time. The show is already causing controversy. The Los Angeles Chapter of the National Organisation for Women calls Simpson 'an admitted batterer' and is promising to protest outside the studios. Bryant Gumble has been pulled from the interview team because he is a friend of Simpson. After hearing the news, he called in sick. If The OJ Simpson Story is a cynical attempt to make a few green ones while the iron is hot, its producers are not alone. Prosecutors Marcia Clark and Chris Darden have signed contracts with The William Morris Agency for prospective book and movie deals. The jury forewoman and two other jurors have signed for an undisclosed amount with Dove Audio, which has already published four books related to the case. YOU don't need me to tell you that Stephen King's The Tommyknockers (Pearl, 9.30pm) is based on the novel by Stephen King. What you might not know is that it stars L.A Law's Jimmy Smits, who tomorrow evening in NYPD Blue takes over from David Caruso. Small world, isn't it? Look out also for Joanna Cassidy, sister of David, both of whom starred in The Partridge Family. The story is the usual King hogwash - something strange appears in the woods and a small town is gripped by fear, panic and evil. The second and concluding episode is tomorrow at the same time. DAVID Attenborough is the only person on the planet capable of producing six, hour-long documentaries about plants and making each one as compulsive as ER, Chicago Hope, the OJ Simpson trial and the F.A. Cup Final rolled into one. In this evening's episode of The Private Life of Plants (Pearl, 8.30pm) Attenborough - who pops up in Britain, Sarawak, the Californian desert and the high bushveld, but always in the same shirt - examines the tricks flowers use to attract insects and animals to pollinate them. THE late Raul Julia stars in The Penitent (World, 12.40am), which is one reason for watching it. Perhaps the only reason. It's an odd little fable, directed by former actor Cliff Osmond, which bites off more than it can chew. Osmond seems to tire of its complexities halfway through and hastily rolls the end credits before it gets truly out of hand. Armand Assante is brooding as the ex-con who seduces pal Julia's wife (Julie Carmen). It's set in a remote village where residents re-enact the Crucifixion every year. This, and all its associated imagery, play a big part in the proceedings. FILMS on Cable Movie Channel: Our Sons (7pm). Two middle-aged mothers whose sons are a gay couple cross paths when one of the young men is stricken with AIDS. Ann-Margret plays an Arkansas barmaid whose long estrangement from her son will end if wealthy Julie Andrews (in her TV movie debut) can deliver her to his hospital bed. The gay couple are played by Tony Roberts and one Hugh Grant - they act out some fairly compelling love scenes, stealing the show almost from the mothers, who are its intended focus. Grant is also in Night Train to Venice at 3am.