Originally posted by Mr. Toad
Three questions then:
Have you decided then that all the blame belongs to the racial aspect and the number/availability of guns is no longer your main argument? 
If so, are you saying that the difference is black on black homicide or black on both black & white homicide?
And, before you answer that......
Have you actually checked the stats by race in the US as compared to Canada?
Mr. Toad,
Mr. Toad! What's all this about an argument? This thread is about a movie which I found... interesting. We're not having an argument! Where did I argue? I'll read walls 3 and 4 if you'll reread my initial post, and you will see that I didn't say anything to start an argument. Of course, for someone like me, the very mention that I have seen that movie is enough for some people to think I'm starting one.

But since you ask, and since your questions are reasonable, I'll try to comment.
- No, I have not decided then that all the blame belongs to the racial aspect. Britain also is multi-racial. But we have fewer than 100 gun related deaths per annum, as compared with the many thousands that the US has. So it's not purely a social/racial issue.
- Having answered No to the first question, the second question is null.
- No I haven't "checked the stats" for homicide by race in Canada. Should I have done? I'll be glad to review yours if you have them, but not if they're written on the side of your movie theatre popcorn bucket.
In the US, however, the black on black homicides would seem to be a substantial proportion of the overall total. That is certainly borne out by the stats for Washington DC where, I believe, 60% of the population is black, and for New York - a city of some 10m blacks - more than any other city in the world (according to a 1980s Trivial Pursuit question). I don't know how many blacks there are in Canada, or whether any of their cities have black ghettos like South Central Los Angeles/The Watts district.
My parents were horrified when I told them in 1980 that I'd be living in Chicago. But whereas the (black) south side was like a war zone, the (white) NW suburbs where I lived were law abiding and peaceful. And I didn't need a gun.

The relatively high US homicide rate stems from a
combination of factors. As you have been at pains to point out, guns on their own are not the problem. But as I am at pains to point out, neither is a multi-racial society: Unlike America, we do not have thousands upon thousands of gun related homicides in Britain each year, despite the racial mix.
A can of petrol for the lawnmower, kept in a cool dry place out of sunlight, is safe. So is a box of matches. Out in the open, petrol spilt on the ground will quickly evaporate. And a lit match will, at worst, burn my fingers. Speaking figuratively, America has a lot of people spilling petrol, and a lot of people playing with matches.