Banshee:
The police honestly do their best. They jump into action and begin looking for clues and start questioning people and everything, but many times there's just not alot of evidence. That makes it hard to figure out much of anything. Eventually the case dries up, and there's no where left to look. People are told to keep their eyes open, but that's still not easy to do.
I think the fact that there have been alot of young white girls who show up in the national news is because of the strange circumstances surrounding the cases, and television news is really designed as something like a ghost story. Since the audience is mostly middle-america middle-class, they are going to tell the stories which might have the biggest factor of fear in them.
Secondly, I think that girls are more commonly abducted then boys are, so they're more likely to show up on the news.