Green’s Dictionary of Slang

1. to identify someone as the perpetrator of a crime; to convict of a crime, thus fitted, found guilty.

1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 3: A sergeant of police was shot in our last scrimmage, and they must fit someone over that.
1895		Truth (Sydney) 5 May 5/7: I got 18 months under the Vag., the police failing to fit me under the confidence trick.
1895		Crowe Aus. Sl. Dict. 29: Fitted, found guilty.
1901		Sydney Sportsman (Surry Hills, NSW) 4 Sept. 2/6: Some got lectured, some got fitted, / Others, too, got off scot free.
1914		Truth (Melbourne) 21 Feb. 12/6: It were not till some time later, / That they fitted him and her, / When him and his frowsy mother / Got a stretch apiece dear Sir.
1919		V. Marshall World of Living Dead (1969) 83: Stretch—two-drags—coomyerlative. Three charges agin’ me—righteous, vag, an’ resistin’. Fitted on first two—turned up on third.
1938		Press (Canterbury) 2 Apr. 18: To ‘fit’ is to find enough evidence to convict.
1953		K. Tennant Joyful Condemned 25: Why they’d fit you with enough time for Methusaleh if they grabbed you with that!
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 28: Fitted Convicted.

2. to characterize; to identify.

1911

E. Dyson ‘The Fickle Dolly Hopgood’ in Benno and Some of the Push 59: Benno grinned approvingly. ‘Strike me, Feathers, you’ve fitted her in one!’ he chortled.

3. see fit up v.¹