Everyone knows that if you’re given the third degree, that you’re under “intense interrogation by police” or some other authority figure.
The police reference has been around since 1900, and is a reference to the Third Degree of master mason in Freemasonry dating back to changes made in 1721, four years after the first Grand Lodge of Freemasonry was founded in London, England. The third degree ceremony involved an interrogation ceremony before the degree was conferred upon the Freemason.
In American, the third degree defined the seriousness of a particular type of crime and is recorded as early as 1865. In 1910, Richard H. Sylvester, Chief of Police for Washington, DC divided police procedures into the arrest as the first degree, transportation to jail as the second degree, and interrogation as the third degree.
And in 1931 the Wickersham Commission found that use of the third degree was widespread in the United States and was misused at times to extract confessions from suspects.
Historically Speaking 