Green’s Dictionary of Slang

a thief, esp. one who deliberately starts fights between others in order to rob them in the confusion.

1845		G.W.M. Reynolds Mysteries of London vol. 2 142: VamperA fellow who frequents public-houses, where he picks a quarrel with any person he has got a ring or a watch about him, his object being to lead the person into a pugilistic encounter, so as to afford the vamper's confederate, or pal, the opportunity of robbing him.
1864, 1867, 1870		Hotten Sl. Dict. 265: Vampers fellows who frequent public-houses and pick quarrels with the wearers of rings and watches, in hopes of getting up a fight, and so enabling their ‘pals’ to steal the articles.
1876		J. Greenwood Undercur. London Life n.p.: It is beyond dispute that in the hands of the experienced horse-vamper the most wretched used-up screw in existence may, for a brief hour or so, be made to exhibit an amount of fire and spirit that if persisted in for a longer period would inevitably shake its ramshackle carcass all to pieces [F&H].
1927		‘Jargon of the Und.’ in DN V 466: vampire, A yegg who travels with hoboes in order to rob them.