?1921 E. Hemingway Ash Heel's Tendon in (1985) 18 Aug. 23/3 An exorbitant price for a simple bump-off job.
1934 R. Chandler Finger Man in Oct. 11/2 ‘They pushed him on to the roadway, filled with lead’... ‘It was a nasty bump-off.’
1975 J. Porter i. 9 Cornering the market in submachine guns and wholesale bump-offs.