Re the "supply-and-demand" thing, there was an interesting article in NewScientist this week about this. Turns out that cheap guns from a particular shop took an average of just 90 days to be used in crimes (or more accurately, to be recovered by police after crimes). When the shop stopped selling them, legal guns stopped turning up in crimes.

Link here.

Sadly it doesn't say whether gun crime overall went down as a result or whether criminals found another source, which seems a bit of an omission.

Graham.