Joan Smith: The crimes that turn us into voyeurs

At the very least, the studio shot and CCTV footage invite us to dwell on Ms Bowman's youth and beauty

Last week, the latest batch of CCTV footage was released to the media and shown on BBC television's Crimewatch programme. The subject was the 18-year-old Sally Anne Bowman, who was sexually assaulted and stabbed to death near her home in Croydon last month. The film showed Ms Bowman on a night out, buying drinks at a bar and chatting to friends. She left the bar with her sister before going to a friend's house, returned to the town centre in a taxi, also captured on film, and was picked up by her ex-boyfriend, who dropped her at her home in south Croydon. Ms Bowman was attacked yards from her parents' house, and forensic evidence quickly linked the murder with a sex attack in Purley four years ago. Half a dozen women called the police the following week, reporting incidents ranging from "peeping Tom" offences to sexual assault.

This is a brutal and horrific crime that has ended the life of a beautiful young woman and devastated her family. But for that reason, and because Ms Bowman was an "aspiring model", it involves even more than most murders an overt invitation to voyeurism. The most frequently reproduced photograph of the dead woman is a posed shot in which she is wearing a white basque and a short blue denim skirt that are identical, or very similar, to the clothes that appear in the frames of the CCTV footage. It is the kind of outfit beloved of teenage and twenty-something young women and adored, for quite different reasons, by defence counsels in rape trials, who have no qualms about suggesting that any woman who dresses in such a way is "asking for it".

One of the perverse features of trials involving sexual offences is that a heavy responsibility is placed on women to behave with the utmost circumspection at all times, to avoid inflaming the lust of strangers and acquaintances, while all but the most violent male behaviour is subject to charitable interpretation. Ms Bowman behaved sensibly, using taxis or getting lifts from friends, and the police suspect that her killer, who may have attacked another woman on the same night, may even have lain in wait for her. She is not in any way culpable for what happened. Yet the pictures, not to mention that loaded word "model", subliminally tell a different story.

At the very least, the studio shot and the CCTV footage invite us to dwell on Ms Bowman's youth and beauty in the knowledge that something dreadful is soon to happen to her; at worst, they invite a link between the confident, knowing way in which she carried her beauty and what was done to her, a link that appeals to deep-seated prejudices about women's sexual power and pride coming before a fall. The fact that girls and women of all ages are attacked regardless of their appearance or behaviour is eclipsed by the focus on a single, atypical incident. And so is the real moral of what happened to Ms Bowman: that every woman is threatened by a minority of men who happen to be merciless sexual predators.