Green’s Dictionary of Slang

(UK?US black/gang) a gang member.

1985		‘Jennifer Blowdryer’ Modern English 57: banger (n): Someone who indulges in gang activity.
1993		K. Scott Monster (1994) 25: The police have a vast array of laws [...] to curtail the bangers’ growth.
1995		Coolio ‘Gangsta’s Paradise’ 🎵 Got my ten in my hand and a gleam in my eye / I’m a loc’d out gangsta, set tripping banger.
2000		Observer Mag. 9 Jan. 13: Bangers are the poor, usually teenage boys who hang out on corners, protecting territory.
2006		G. Iles Turning Angel 399: You sent a lot of people to Huntsville Prison. Bangers, killers, Klan, everything.
2013		J. Stahl Happy Mutant Baby Pills 16: MacArthur Park, where twelve-year-old 18th Street bangers kept the stuff [i.e. heroin] in balloons in their mouths.
2017		1011 ‘Kill Confirmed’ 🎵 Dem man been new bangers, they ain’t ever touched no one (some dickheads).
2021		T. Swerdlow Straight Dope [ebook] If you want some old banger to give you a minute, tell him you’re talking to your mom.