I shall come clean and confess that as news of the murder of Jill Dando broke, the first question to flit across my mind was not "Whodunnit?", but "Who she?". I suspect I was not alone: before her death, who but the most ardent of Crimewatch fans (and you have to worry about them) would have been able to pick her out from a line-up of identikit BBC blondes? She even referred to herself as "Blando", and this anodyne anonymity is precisely what made her murder so shocking.

In All About Jill, David James Smith attempts to place Dando's very public death in the context of her life, on- and off-screen. A book almost as mawkish as its title, it covers her baptism, her life-threatening heart surgery as a baby and the fitting for a wedding dress she would never wear, all within the first chapter.

Smith hovers over any incident that might reveal "nagging insecurities", "loneliness and uncertainty" or, better still, "repression", yet for all this, Dando's private life is simply not the stuff of powerful biography. The golden girl from Weston-super-Mare worked hard without having to overcome any particular difficulties; she played hard, too, but had never checked in to the Priory; she caused no bitter family feuds; and if she wasn't as virginal as Middle England would have liked, well, nor was she a home-wrecker or a heartbreaker.

In an attempt to suggest a motive for her murder, Smith hints heavily at "the darkness of Dando". But aside from two calls to sex chat lines made from her mobile phone in the months before her death, her "murky" past amounts to little more than a collection of Cliff Richard singles and an address book listing the likes of Jeffrey Archer and Sophie Rhys-Jones. The worst anyone can say about Dando is that she was ambitious and lacking in dress sense. Even her euphemistically "active" social life amounts to little more than a few lonely one-night stands and some "criss-crossing" relationships.

As Dando herself often said, she was a professional chameleon, a fact oddly confirmed by the decision of her fiance, Alan Farthing, to bury her with her make-up bag. In the end, she was swallowed up by her BBC role, and her own story - that of the Radio Times cover girl gunned down on her Fulham doorstep - turned out to be far more lurid than any that ever scrolled across her Crimewatch autocue.

Another person who had trouble remembering just who Dando might have been was the crook-turned-crime pundit John McVicar; but that hasn't stopped him from writing a book ostensibly all about her murder. The then crime and legal correspondent of Punch magazine was holidaying on the island of Rhodes, trying to bed a 20-year-old Finnish student whom he had met over the internet, when he read about Dando's death in a day-old news-paper. Realising who she was ("not too bright, beaming air-hostess smile, blonde, attractive but never sexy"), his next question was: why had the gunman not gone instead for the Crimewatch anchorman, Nick Ross? This pretty much sets the tone for Dead on Time, a rambling investigation into how and why Barry George executed Jill Dando.

Back in England, McVicar slithers into his cycling leggings and pedals off down a series of investigative cul-de-sacs, considering in turn the jilted ex, the "nutter", the Serb and Dando's innocent next-door neighbour, before deciding that George was indeed guilty. Beyond what came out in court, he offers little new information on "the kill", as he calls it. What he does provide, however, is a sublimely surreal motive fusing together Queen lyrics, the film Highlander and Ninjutsu mythology (in which "Dando" is a monster).

David James Smith remains sceptical that Barry George was the killer, but where his account lacks a villain, John McVicar has forgotten the victim, and his unpleasant book suffers as a result.