I dont want to give ideas to people, but it seems to me that one could escape the long arm of the law with the help of pheromones ...

Think about it, if you are seen by a close proximity witness at the scene of a crime, and during the next days/weeks you change your appearance (shave, loose some weight or whatever) and put on some heavy doses of some pheromone, when the time comes for that witness to identify you i imagine he will have a hard time doing that in a court or sometime when it comes to close proximity recognition. I bet average Joe's brain will start having serious doubts about who's he seeing in court.