As Questdriven has pointed out, gun ownership has no direct correlation with homicide rates.
I am pro second amendment. Philosophically, I believe the right to bear arms empowers the fourth branch of government oversight: the people. Gun ownership is about as democratic is it can get: the First Amendment gives the people the right to speak up. And the Second Amendment gives the First Amendment, as well as all others, teeth. A distribution of power, so to speak. A right written on paper is meaningless unless it is respected. And an armed population demands respect.
Criticism: But American people are no match to the government's military! They [the gov] has nukes and missile submarines and stealth bombers!
Retort:
1. When governments in history have turned on their population, it always happened slowly. Most soldiers are ordinary people, and have to be indoctrinated into atrocity. An armed population would require a sudden atrocity to pacify, as an armed population would not tolerate the slow erosion of their freedom. I doubt many soldiers would comply, and I doubt the government would risk exposing their true nature before the yolk of tyranny has had time to entrench itself.
2. It takes less effort to arrest someone you are told to when they don't resist. When they do resist, it forces every soldier to seriously consider what it is they are doing.
3. Nukes are good for wiping enemy cities of the map, not rooting out a civil rebellion. They are just indiscriminate like that.
4. History. And recent history. A small-arm based insurgency is quite effective against superior military power. For example, Iraq, Afghanistan, Ireland, Syria, Egypt, America (revolutionary war), Libya, Soviet Union, Vietnam, France, ect.
5. Deterrent.
Criticism: But guns kill people! They should be illegal! Then it would stop.
Retort:
Murder is illegal. You think someone willing to violate that rule would hesitate to purchase a firearm illegally?
Guns are in America. There are probably over 350,000,000 of them. The time for gun control is over. They are here to stay. Make them illegal, and law-abiding citizens would lose them. Make them illegal, and criminals would not care, since they purchase them illegally anyways, or use them in violation of law.
For example, did you know that almost all mass-shootings occur in "gun-free" zones? All "gun-free" zones mean is that the only people who will have one will use it to kill, since it is illegal to carry one to stop those who would use it for ill.
P.S. Look at the stats of crimes which were prevented because someone was lawfully armed. There would be a lot more violent crime completed if those who had the power to stop said crimes were unarmed victims instead.
They polled a bunch of prison inmates, and the number one deterrent to committing a violent crime was the fear that the victim was armed. A city which has banned all lawful gun-ownership would be a mecca to criminals. Sorta like Chicago.
Remember folks, the cops are there to solve crimes. Not to prevent them.