Since when was the UN is concerned about fair trials?

The UN has no credibility making statements about fair trials. I do not read about the UN's concerns over the detentions in North Korea, China, Iran nor Russia. Where is the UN's concerns when the Palestianians execute suspected collaborators, without a trial?

But hey at least they are concerned that the insurgents killed two of Saddam's lawyers:

"We're concerned already by what we have seen, we are concerned by the murder of two defence lawyers and the serious wounding of another," Pace said in Baghdad.

Why doesn't the UN do something about the prisoners in non Western controlled locations?