Stretching more than a kilometre through one of Zurich's most run-down areas, Langstrasse or "Long Street" certainly lives up to its name. For every clothes shop or jewellery store, there are three times as many brothels, strip-bars, erotic cinemas and sex shops.
By nine o'clock in the evening the street is starting to liven up: music blares from rival bars, residents give way to lone men and scantily-dressed women, and two of the scene's regulars are just beginning their trawl through the district's hot spots.
Hans-Peter Meier and Kurt Beck have been working for the city's vice squad for more than four years. And although they have other beats to keep an eye on, it's the nights on Langstrasse that tend to be the busiest. Beck is the first to stop. Underwear, red light, the lot. Now we just wait to see if she winks at me or beckons me in. If so, we can issue her with a fine. There is little chance that the woman at the window will make such a mistake.
Even in jeans and casual shirt, Meier and the rest of the vice squad team are well known to the city's prostitutes. So it's enormously difficult to stop the illegal prostitutes.
We would need to have a couple of new faces every week or so which just isn't possible. After knocking on the door, Meier and Beck are welcomed in like old friends by two scantily-clad North African women. Their work permits are in order. Meier and Beck also use the opportunity to inform the women about the coming change to the law on window prostitution. The conversation is not all one-way, however. One of the women wants to know why the police don't concentrate on tracking down the illegal prostitutes who she says are undercutting the prices of the registered women.
