Green’s Dictionary of Slang

1. (US tramp, also stoop tobacco) a cigarette stub, picked up in the street.

1927		‘Jargon of the Und.’ in DN V 465: stoop tobacco, Cigar butts.
1931		Irwin Amer. Tramp and Und. Sl. 184: Stoop Tobacco.–Cigar and cigarette ends picked up in the streets, the picker having to bend or stoop over to reach them.
1937		J. Curtis You’re in the Racket, Too 187: ‘You can’t kid me you had to kip out last night and here you are strolling around smoking bloody cigars.’ ‘Never heard of stoopers? I picked this bastard up in Bayswater Road.’.

2. (US) a person who forages for betting tickets on the ground at racetracks.

1952		in Lethbridge (Alberta) Herald 22 Mar. 14/4: A stooper is a fellow who wanders around looking for cashable pari-mutuel tickets which may have been dropped carelessly.
1961		J. Scarne Complete Guide to Gambling.