Edam, I would say that the first step would be to acknowledge that the problem happens. It's easier to ignore these cases rather than act on them.
A couple of months ago I posted a thread asking for messages of support for the families of women and girls who have been raped AND murdered. (it's not that I have a morbid look of the things, they were more than 300 victims at the time and all the murders had been commited in the space of 10 10 years in my former city). I was expecting a better reaction, but very few people cared. I believe if we had the courage to look at these things and try to do something about it, then things could change. But as long as the people decide to ignore them, the things will remain the same.
As a postscript to this... since my last post at that thread at least other 3 women had been killed. Was rather shocked to be at the city in december and everybody seemed more concerned about the bad name the city was getting rather than the crimes themselves