Green’s Dictionary of Slang

bugger n.2

[bug n.4 (2a)]

(US Und.) a pickpocket.

[US]Matsell Vocabulum.
[US]J.D. McCabe Secrets of the Great City 359: The Detectives’ Manual gives a glossary of this language, from which we take the following specimens [...] Bugger. – A pickpocket.
[US]Trumble Sl. Dict. (1890).