My understanding is that the Age of Criminal Responsibility in the jurisdiction of England and Wales is 10 years of age, whereas in Scotland it is 12 years of age.
Assume, for the purposes of this question, that a young man commits a murder at the age of 10 in England. He then manages to flee to Scotland, before any court proceedings are conducted. His escape to Scotland could have been pre-arrest, or post-arrest.
In the above example, I am curious as to what might happen? I would assume that the offender would not be tried in Scotland because he is under their age of criminal responsibility, not forgetting to include the fact that the offence was committed in England. The next thing would be some type of "extradition" (assuming this is a valid term within the UK) which seems unfair as his conduct was not a crime under the laws of Scotland given his young age.