You have to put things into perspective. Indianapolis has something like 40 murders this year. They had 8 within 12 hours last week. Am I afraid to go to Indianapolis? Absolutely not, I am there nearly every week. I have never been approached by someone with a gun nor have I ever seen someone with a gun assaulting anyone. Most murders are drug related and if you are not in the business of buying or selling drugs your chances of being murdered here is no worse than in Canada.
Come to the U.S., be aware of where you travel. It is pretty easy to research any major city to see where it is safe to visit. The vast majority of this great country is very safe to visit.