Green’s Dictionary of Slang

wirer n.

[wire n.2 ]

an expert pickpocket who uses a wire to remove objects from his victims.

[UK]‘Ducange Anglicus’ Vulgar Tongue.

In phrases

fine wirer (n.) (also fine worker)

the most skilful grade of pickpocket, esp. one who steals from women.

[UK]J. Greenwood Seven Curses of London 89: Long-fingered thieves expert in emptying ladies’ pockets – fine wirers.
[US]A.H. Lewis ‘The Humming Bird’ in Sandburrs 24: Mollie’s d’ flyest fine-woiker on Byrnes’s books [...] D’ supers has to be yellow; d’ white kind don’t pay; an’ d’ rocks has to be d’ real t’ing. In d’ old day, Mollie was d’ king of d’ dips, for fair!
[US]A.H. Lewis Boss 168: A mob of them Western fine-workers are likely to blow.