This has been a known phenomenon for a long time. There's a quote from Homer two and half millenia ago that says something to the effect of, "The sword calls for violence." Paraphrasing, because I can't really remember it, but the attitude displayed in the above quote definitely helps me solidify my belief that beat cops shouldn't have guns. Edit: "The blade itself insights to deeds of violence." Big ups to CashewGuy for the correction via pm.
I don't want to detract from your point, but it should be incites, not insights. Personally, I'm a supporter of second amendment rights, but I can understand the desire for reasonable limitations on that right because of that very phenomenon. No matter what the policy, everyone's end goal should be a more peaceful society. Criminalizing, banning or otherwise outlawing all weapons isn't the best solution, in my opinion, but neither is advocating for the promulgation and dissemination of weapons among the public, including the police. Murder is a terrible crime and advocating that people use lethal force to protect themselves from any perceived threat of harm is one very small step away from advocating murder itself.