Killing one woman who is selling sex, it appears, is merely regrettable. Any more and all hell breaks loose.

Many of the reasons for this are pretty obvious.

Popular culture has given full expression to human fear and revulsion of, and fascination with, the psychopathic multiple killer. But a large part of the reason why one prostitute's death is easily ignored and a connected series of them reviled is driven by punitive ideas about how much a prostitute should be expected to risk for her sins.

A woman who works in this criminalised part of the sex industry is seen as someone who is deliberately putting herself in danger. When the worst happens, to a large degree, she is considered to have brought it on herself. But when there is clearly a maniac on the loose, systematically targeting women, then the balance of risk is disturbed. No woman deserves to be sought out for murder quite so intently. Not even a prostitute.

Few women work the streets because they like it.

They do it because they consider themselves to have no alternative.

But rather than telling them to stay at home, it might have been kinder for the authorities to have told the women at risk that they could go to their doctor and get prescriptions for their heroin, which might also be a way of keeping them off the streets more permanently.

One study found that 98% of sex workers on the street had a drug problem. Unfortunately, just as street prostitution is stubbornly seen as a feckless choice rather than a rock-bottom consequence of having no perceived choice at all, heroin abuse is viewed as a moral dereliction rather than an addictive illness.

Much, inevitably, has been made of the death of 25year-old Gemma Adams, because she is from a middleclass background, from a childhood strewn with Brownies, horseriding and piano lessons. She "fell in with a bad crowd" and became addicted to heroin. She lost her job in an insurance company because of her chaotic drug use. She ended up on the streets. Bad choices, all.

The British government suggests relaxing restrictions on brothels so that three girls can work together on private premises, while at the same time balancing a zero-tolerance approach to street prostitution by facilitating further choices for safer "inside" work. Now, enterprising sex workers can work for themselves, as an alternative to working as escorts or in saunas.

The irony is that those who run escort services or saunas are no more enamoured of drug-addicted employees than are the managers of insurance offices.

Addicted, chaotic, mentally ill girls leaving care or abused women . . . even older, less attractive or less personable women . . . find it hard to get work in other, less dangerous parts of the sex industry, for much the same reason as they can't get work anywhere else. They're just not very employable. They're not good material for entrepreneurial self-employment either.

For street workers, the way they get money is usually just one more nasty and unpleasant detail in a nasty, unpleasant life. Public revulsion for street girls is reflected in law and government policy. Amid the horror in Ipswich there is a chance to see the extent to which these add further degradation to lives already subsumed by it.