This is a question posed to any police officers reading this (or simply someone that wants to jump in). I was a cop for 13 years and always carried a knife of one kind or another. Just what cops did. Had automatic (switch blade), Emerson Karambit, and one of my favorites, a Crawford that is a deadly looking mother. For the last couple of years have been studying Kali, which, as some of yo may know, has a big emphasis on knives. Got in a discussion with one of my instructors and we started discussing the use of a knife as a police officer in a didactic manner. So my question came, when would a cop use his (or her) knife? I've heard the old rationalized argument :to cut a seat belt". Sure. Better instruments for that, if and when you ever actually have to cut a seat belt. Try cutting an old one sometime. We really couldn't come up with a viable reason for a cop actually using his knife, certainly in a defensive situation. First, I had a pistol. Had a small back up pistol, but not always. A Taser. A collapsible baton. And the knife by most, me included, was clipped in the right pocket. See how fast you can get to this. If you can't get to your gun, can you access the knife any easier. So keep in mind, from the legal perspective, a knife is a deadly weapon. And extremely close range. So when you use your knife, you are trying to kill the person. And now comes an important issue, do you really know how to use the knife effectively? And it's a given, that an untrained person is probably going to not be terribly disadvantaged over a trained person when it comes to doing damage to another person. I'll be interested to see the comments to this.