Green’s Dictionary of Slang

turning joint n.

[joint n. (3b)]

(US Und.) a place where innocent people were brought to be swindled out of their legitimate money in exchange for counterfeit notes.

[US]E. Townsend ‘The Reward of Merit’ in Near a Whole City Full 164: I’m staked out here for Billy. He’s got a come-on from New Jersey that I’m to steer to the turning joint. Mike Golden’s place was a headquarters for ‘green-goods’ swindlers [...] where victims exchanged good money for waste paper.