Interested in buying a folding knife? Where do you start? What important features should you look for? What about blade shapes, serrated edges and the mind-boggling number of different styles, locking and opening mechanisms, blade-steels and handle materials out there? Why are there so many, what's the difference and which is the best? As a cop and first responder, how do I know which knife is the best for my job and for my use off duty? How and...