James Wright and Peter Rossi (originally pro-gun control liberals, both of them)did the writeup on the DOJ felon survey in the 1980s Armed and Considered Dangerous, 1874 convicts in 18 prisons in 10 states. Most felons expected to easily be able to acquire weapons within a week of leaving prison.
o Half of felons cited dealers in contraband--smugglers and fences--as their main source.
o One quarter expected to be supplied a gun by a fellow criminal on the outside.
o One eighth expected to steal their own guns.
o One eighth (~13%) expected to get guns from pawnshops or gunstores, usually by having a friend or relative with a clean record buy for them.
Wright and Rossi ended up losing their blind faith in gun control, the more they studied the issue.
Sources of theft include gun shipments between gun makers and wholesalers or retailers (especially for full-time dealers in contraband, including drug dealers and fences). Theft, bribery or extortion from military or police with access to arsenals is a source of serious weaponry.
So, we have at most 400,000 firearms criminals in America, and 80,000,000 lawabiding gun owners. What should be the focus of laws aimed at gun violence? Why, of course, it is the 80,000,0000 that are the focus of gun laws, not the 400,000.
The CDC in 2003 and the NAS in 2004 conducted critical reviews of gun research and concluded that there is no evidence to indicate that any of the existing gun control laws have a measurable benefit.
How can they? I believe that controlling criminal violence through laws aimed at legal guns and their owners is comparable to controlling prostitution (illegal sex)by continually adding restrictions to marriage licenses (legal sex).
Wright and Rossi, Second revised edition described here:
http://www.amazon.com/Armed-Considered-Dangerous-Peter-Rossi/dp/0202362426/