Green’s Dictionary of Slang

(US black) to look for trouble, to start a fight.

1927		‘Max Brand’ Pleasant Jim 305: Lew was head-hunting.
1938		C. Himes ‘Pork Chop Paradise’ in Coll. Stories (1990) 256: The head-hunting guards had a field day on black rapists.
1980		E. Folb Runnin’ Down Some Lines 106: Headhunting [...] looking for an opportunity to start trouble.
1999		(con. 1979–80) A. Wheatle Brixton Rock (2004) 18: Flynn and his posse, as the ghetto press would have it, were headhunting Brenton to exact some sort of revenge.