This case of Chemical Ali' (to be hanged within days) causes me to enter a caveat: where penal custody for life (a life sentence) is not secure, enabled or guaranteed, taking a dude out back and shooting him is permissible.
I take no position on Ali Hassan al-Majid's guilt or innocence. He's been sentenced (for the fourth time) to death by Iraq's high criminal court for ordering slaughter of Kurds in 1988. You can read about details here and elsewhere on the 'Net. His (relative) guilt may be beyond question, but it also beside the question.
So, I'm not making this about Chemical Ali'; I just consider him as a poster boy.
The question is, how can his re-release into society be definitively prevented. As the Guardian points out,
...the Guardian has learned that the US detention centre in which Majid has been held since being captured six years ago will continue to house prisoners until August, despite being scheduled to close on 31 December as part of a much-heralded security agreement between Washington and Baghdad. The status of forces agreement signed between both states had flagged the closure of the Camp Cropper detention centre as a milestone of security progress.In the political disorder that follows post-Bush Iraq, there is no insurance this poster boy won't somehow gain his release.
Poster Boys like him are captured and tried all over the world, every day. Some can be sent to the Hague. But not all.
Of course, if Guantanamo didn't have to be closed to satisfy certain symbolic purposes; if it could be internationalized under United Nations auspices, Gitmo could serve as another secure International House of
(But that's another story.)
So, If Chemical Ali' is guilty of the heinous acts of which he is accused, I'll pass on his case.