See report from the Guardian on the James Bulger case.

There is no other legal or social arena where we give children complete responsibility at 10, mostly for good reason. The important thing is the consequence of being over the age of criminal responsibility, not the age per se. Other countries with a very low age (10 or less) usually have a period where responsibility is not absolute until mid-to late teens, or where the response to breaking the law is welfare-oriented rather than retributive. For example, the age in Scotland is eight but the consequences are almost all framed within the welfare system.
Verdict: Age isn't the issue





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Note added at 11 mins (2005-11-28 13:22:53 GMT)
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I mean 'over the age of criminal responsibility' (see text I quote)