Green’s Dictionary of Slang

1. (Aus.) to leave home and become a bushranger.

1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 158: A bush-ranger [...] that’ll be the long and short of it. You may as well know it now, we’re going to ‘turn out.’.
1901		‘Rolf Boldrewood’ In Bad Company 142: One of the most desperate, bloodthirsty bushrangers that had ever ‘turned out’ in New South Wales.
1906		New Boys’ World 22 Dec. 78: To ‘turn out’ meant becoming a bushranger – it was a camp-fire phrase.

2. (US Und.) to free a criminal from arrest.

1899		S.F. Call 2 Apr. 25/5: When a prisoner is convicted he is said to be ‘settled’; if released he is turned out.
1910		J. Sullivan ‘Criminal Sl.’ in Amer. Law Rev. LII (1918) 890: ‘Turn out’ is to discharge from arrest and put a man on the street.
1932		Seabury Report 24: [T]he clerk notifies the Magistrate that, in his opinion, the facts are insufficient to justify the drawing of a complaint, whereupon the Magistrate, without taking any testimony, turns all the defendants out.
1950		Goldin et al. DAUL 229/2: Turn out, v. To secure the release of a co-defendant by pleading guilty and assuming full responsibility for the crime charged. [...] 2. To parole; to acquit; to discharge from court or prison.

3. (US Und.) to become a professional thief.

1969

B. Jackson Thief’s Primer 74: Why did you turn out? Why did I turn out stealing? [...] I don’t know. I have no idea.