Times Online
http://www.timesonline.co.uk/article/0,,564-1361452,00.html
November 17, 2004
Questions answered
When someone is given the “third degree”, what is it? What are the first and second?
In traditional Freemasonry, obtaining the first three “degrees” requires passing progressively more detailed cross-examinations about the tenets and rules of Freemasonry. For the third and most important degree (master mason) it is particularly detailed and lengthy.
As Masonry has been traditionally popular in law-enforcement agencies, “give him the third degree” became an “in” reference to a particularly gruelling police questioning.
David Norris, High Wycombe, Buckinghamshire
Further Reading:
UK Freemasonry in the News, have the 'Brethren' finally met their Waterloo?