Madeleine?

I had the same thinking as you when I heard this on the news and saw the sketch of the man. But, if you think about it, the people who abducted her had her in public view, where a lot of people could see her. So, by releasing the sketch, they might be hoping that, in their travels, they will be recognized and more people will be on the look out for couples traveling with a little girl. It also helped that they had the cups and straws of the couple and little girl to help identify if it was even Maddie and who her possible attackers are.