Illegal guns are former legal guns. S&W doesn't run a factory that only sells to criminals -- those legal guns are diverted to criminals, via the generally lax attitudes of American gun owners.
I have since left California and moved to a state where everyone is heavily armed. Now my rifles are pea-shooters in comparison to what everyone else around me has. Firearm crime is a very rare occurrence here.
Delaware (10) 93 973,764 9.6
Iowa (19) 294 3,155,070 9.3
Minnesota (27) 465 5,639,632 8.2
California (06) 2,945 39,512,223 7.5
Connecticut (09) 190 3,565,287 5.3
Rhode Island (44) 48 1,059,361 4.5
Hawaii (15) 62 1,415,872 4.4
New Jersey (34) 368 8,882,190 4.1
New York (36) 804 19,453,561 4.1
Massachusetts (25) 247 6,892,503 3.6
Including only homicide, california is 3.19 per 100k and my state is 2.51 per 100k. Sadly I can't get it to drill down to my county. They also do not include justifiable homicide as a data point.
I am not going to be able to get the exact same figure as you since the way the search form is set up it is pretty easy to get slightly different numbers. But the only state from the last 3 years of data that would seem to fit your comment is Minnesota. Obviously if you move away from some of the largest metropolitan areas in the US crime rate goes down. But that does not even matter. California still falls in the bottom 8 states despite having several large, difficult metro areas, and the highest percentage of its population living in urban areas of any state, at 95%. In contrast, Minnesota is at 17th, with 73.3%.