From the article:
The British government decided it was “in the overwhelming interests of the United Kingdom” to make Abdelbaset Ali Mohmed al-Megrahi, the Lockerbie bomber, eligible for return to Libya, leaked ministerial letters reveal.
Gordon Brown’s government made the decision after discussions between Libya and BP over a multi-million-pound oil exploration deal had hit difficulties. These were resolved soon afterwards.
It get's better:
The correspondence makes it plain that the key decision to include Megrahi in a deal with Libya to allow prisoners to return home was, in fact, taken in London for British national interests.Better and better:
Two letters dated five months apart show that Straw initially intended to exclude Megrahi from a prisoner transfer agreement with Colonel Muammar Gadaffi, under which British and Libyan prisoners could serve out their sentences in their home country.
In a letter dated July 26, 2007, Straw said he favoured an option to leave out Megrahi by stipulating that any prisoners convicted before a specified date would not be considered for transfer.
More nauseating details follow which I won't bother to copy and paste.
If they had the death penalty and used it then this wouldn't be a problem.