Green’s Dictionary of Slang

take-off n.3

[take off v.1 (4)]

(US Und.) an armed street robbery or mugging; also attrib.

[US]R. Woodley Dealer 23: ‘If they really checked it out, I think they’d find that the crime rate, stickup-wise, takeoffs, is higher than it was’.
[US]Sepe & Telano Cop Team 78: Automatically such a person [i.e. displaying their cash] becomes a target for a ‘take-off.’.
[US]R. Sabbag Snowblind (1978) 100: If [...] a take-off man comes at him and there are three kilos at stake – call it $150,000 – the take-off man is going to come in on the tail end of an M-16.

In compounds

take-off artist (n.) (also take-off man) [artist n. (1)]

(US Und.) a robber, rapist or killer.

[US]J. Mills Panic in Needle Park (1971) 42: Nick was a takeoff artist, and a good man to ignore. He supported his habit by taking off (robbing) connections, and almost anyone else in the junkie world who appeared to have money.
[US]R. Woodley Dealer 5: The gun is not for the cops. The gun is for the takeoff man in the street.
[US]Sepe & Telano Cop Team 78: The pair of suspected ‘take-off’ artists.