Skin color may be genetically controlled, and police may be able to use this information.
http://www.npr.org/templates/story/story.php?storyId=5055391
But police officers are likely to be interested, too. Already, some officials are testing DNA left at crime scenes to get clues about what the culprit might look like. Tony Frudakis runs DNAPrint Genomics, a Florida-based company that uses gene markers associated with geographic ancestry to give police a general sense of whether someone might look more black or white. In one case, he says, such "DNAWitness" testing helped recently track down a serial killer in Louisiana.
I think that this study is extremely interesting, however I think it's a little sketchy to try and change the color of your skin. For some reason the first thing that came to my mind was Michael Jackson's skin 'discoloration'. It looked totally unnatural (as it was) and changed his whole look. I guess I just don't understand why scientist even care to change the color of ones skin, and why they even find it logical to spend that much time and money researching the findings when they could be putting it to a better use.