Green’s Dictionary of Slang

good adj.2

[orig. used on frontier as good Indian, a dead Indian]

worthless or dead, esp. of an enemy or a criminal.

[US]Congressional Globe 28 May 2638/3: I like an Indian better dead than living. I have never in my life seen a good Indian [...] except when I have seen a dead Indian.
[UK]W. Shepherd Prairie Experiences 62: On the frontier a good Indian means a dead Indian.
[US]Ariz. Wkly Jrnl-Miner Presscott, AZ) 13 Aug. 1/7: Good Indian: a dead Apache.
[US] ‘Jargon of the Und.’ in DN V 448: Good, Dead ‘The old push is all good now’.
[US]Irwin Amer. Tramp and Und. Sl. 88: Good. — Dead, when applied to a criminal.
[US]Monteleone Criminal Sl. (rev. edn) 103: good Dead.
[US](con. 1920s–30s) J.O. Killens Youngblood (1956) 21: Don’t shoot that nigger [...] Just muck him up good fashion.