Consider gun ranges. Everyone is armed, yet no one is killed.
The problem is the image guns have; (my opinion respectfully disagrees with yours, unlike many gun nuts who get pissed off at statements such as yours) many people see them only as dangerous and tools to destroy. I see them as dangerous and tools to protect as well. Guns are so entrenched in American culture (what little culture we have) that they are quite ubiquitous. Gun control efforts simply remove guns from law-abiding citizens, and those who would do harm with them don't care, because now those whom they would harm are disarmed.
Cite? No sources. Just my opinion. What's overall gun ownership in Newark like?
Google found this: http://www.city-data.com/forum/new-jersey/1141975-crazy-nj-gun-laws-these-laws.html It appears they have somewhat strict laws, which can tend to "scare" law-abiding citizens into now owning/carrying guns. This, however, has no effect on the criminals, and now they know their targets are not armed.
Now if guns were much easier to get, criminals would get more, definitely, and crime would probably spike, but as responsible citizens got armed as well, crime rates would probably settle down to lower than what they began at as criminals start getting shot back at.
All conjecture. I'd like to see someone with the resources study this more thoroughly and properly, but there is so much bias in gun control that it'd likely be done by gun nuts like the NRA (I'm a part of, I believe they are a necessary evil in our times, but they are hugely sensationalist) or anti-gun nuts like the Brady Campaign.
Guns are enablers. As authority (from whomever) increases due to increased weapons (guns), then our ability to say "no" decreases unless we similarly escalate. Some other countries don't have such problems, I think, because it is SO much more difficult to get guns into the country, so very few criminals are even able to get guns.