Not a McKinnon reference I hope - he's 45, and has Asperger's rather than full-blown autism.
I believe most of them, like the UK, apply "dual criminality" criteria (i.e. it must be a crime in both countries) as well as requiring a fair trial and generally ruling out the death penalty before extradition can proceed, as well as restricting subsequent charges (extradite someone for X, you can't generally prosecute them for Y without getting the extraditing country's approval). "Chemical castration" can sometimes be used I think, but with the patient's consent as part of rehabilitation - I doubt anywhere Western would extradite to a country like Saudi which uses mutilation as punishment! Refusing to extradite to countries which themselves refuse to extradite if the positions were reversed seems quite reasonable - these treaties are usually mutual, though I don't know if we refuse to extradite to France or Russia because of their own refusals.I pause when the fugitive is a national of the country he has fled to, and I would not return him if the crime he is accused of is not a crime in his homeland, or if the penalty on conviction is likely to be regarded (in the homeland) as inappropriate or unduly harsh (such as emasculation for child rape - see above; barbaric acts of revenge should never be part of a discussion about justice). I would also not return him (for political reasons rather than reasons of justice) if the country seeking extradition would not agree to extradite its own nationals accused of the same crime elsewhere, or if it were using the extradition process to circumvent proper procedure (e.g., seeking extradition in order to allow a third country to then apply for extradition in order to answer totally different charges).
The judiciary isn't reneging on anything: it's the prosecution who offer a deal, and all they can ever offer is that they will ask the judge for a particular sentence: the judge is still free to sentence as he sees fit, subject to whatever the law sets as minimum and maximum sentences for that offence, and of course both sides also have the right to appeal against the sentence if they feel it was too harsh or too lenient. (They can make guarantees about prison conditions, though, as in McKinnon's case to allay fears about ) Had the same circumstances occurred today, the outcome would have been very different. The prosecution in the 70s offered a very generous plea deal in order to avoid having to put the 13 year old victim on the stand to testify, because at that time forensic evidence wasn't as developed as now; in 2011, they'd have had the DNA match to convict with, and he'd have faced a statutory minimum sentence of 15 years.I also pause if the country is prepared to compromise its system of justice by saying, if you plead guilty to a lesser charge than the crime we think you really committed, we will give you a less harsh penalty ... especially if, after that compact has been made, and the accused has burnt his bridges by pleading guilty, the judiciary reneges on it by threatening a more severe penalty. After all, he might have been innocent, but saw no way of avoiding a guilty verdict in such a system.
Thorne: a jury acquittal is, with very rare exceptions, final thanks to double jeopardy (in the US); dropping charges, much less so. In particular, criminals here often get double jeopardy protection by "asking for other offences to be taken into account" in sentencing, which protects them since that offence is now covered by this sentence as well. Having run away before the court case was concluded with a sentence may well mean it's not too late for the prosecution to argue the other five charges after all. I've seen media reports saying both options, so it's hard to be sure unless they manage to get him extradited in the end.
Ironically, part of the original intended sentence was deportation, after an alarmingly brief jail sentence of a few months; to escape that, which would have meant the freedom to roam the whole EU, he has spent decades largely confined to France for fear of arrest and extradition attempts. With hindsight, perhaps he'd have been better staying to receive and serve the sentence instead!