Green’s Dictionary of Slang

(US Und.) a gang of thieves.

1931–4		D. Clemmer Prison Community (1940) 336/1: troupe, n. A gang of pickpockets, safe blowers, or other thieves who steal together.
1937		(con. 1905–25) E.H. Sutherland Professional Thief (1956) 27: The working group of professional thieves is know as a mob, troupe or outfit.
1947		L.J. Valentine Night Stick 222: They nabbed the late, notorious Nicky Arnstein and his gang. Securities to the value of $1,500,000 had been stolen by the Arnstein troupe.
1952		C. Hamilton Men of the Und. 325: Troupe, A mob of thieves.