To give someone the “third degree” is to subject a person to an intensive and prolonged police interrogation that could include the use of physical force and/or mental torture for the purpose of obtaining confessions, testimonies, and other information.
For example, in the bad old days:
“Okay boys, the D.A. wants a confession. Rough him up, give him the “third degree”, and none of that “I know my rights” stuff in this precinct.”
Or an impending “third degree” in a light-hearted vein.
“I dunno, Frank. It’s pretty late, you’re pretty drunk. When you get home, your significant other is bound to give you the third degree.”
Emerging from American big city police argot from around the turn of the 20th century, the term “third degree” drew on a familiarity with the rituals of Freemasonry, a semi-secret fraternal order which enjoyed immense popularity at that time and is still pretty popular now.
The expression “third degree” referenced a lengthy Freemason ceremony whereby an individual received the high order of Master Mason. In this ritual, supplicants were required to undergo extensive questioning, handle “sacred” objects, and display knowledge of clandestine handshakes and other activities and artifacts.
In other words, initiation into the Masons’ Third Degree was a secretive, time-consuming procedure in the same sense that an elaborate police interrogation would be.
Third Degree in Films
Perhaps the most recent depiction of the “third degree,” almost by the book, was in the animated feature The Lego Movie (2014).
But perhaps the most glamorous interrogation appears in the haunting movie mystery Laura, released in 1944.
Laura—now there was a dame!