Green’s Dictionary of Slang

(US) a generic term for the world of professional criminals; thus in sing., a criminal.

1926		J. Black You Can’t Win (2000) 93: ‘This party [...] is one of the Johnson family.’ (The bums called themselves ‘Johnsons’ probably because they were so numerous.).
1930		‘Dean Stiff’ Milk and Honey Route 208: John family — This term is sometimes applied to the farmers, sometimes to the police, and again to the yeggs.
1933		Ersine Und. and Prison Sl. 47: Johnson family. A group of men and boys who once frequented the jungles. The men were yeggs, and most of the boys were broncos.
1935		A.J. Pollock Und. Speaks 7/1: Belongs to the Johnson family, a safe-cracker.
1944		C.B. Davis Rebellion of Leo McGuire (1953) 163: A working Johnson’s better off without a steady muff.
1950		Goldin et al. DAUL 111/1: Johnson family, the. (Chiefly South-Central and Southwest) The underworld. [’One of the Johnson family’— of, or friendly to, the underworld; right.].
1988		W. Burroughs foreword in Black You Can’t Win (2000) 9: I learned about the Johnson Family of good bums and thieves, with a code of conduct that made more sense to me than the arbitrary, hypocritical rules that were taken for granted as being ‘right’ by my peers [...] A Johnson pays his debts and keeps his word [...] He is what they call in show business ‘good people’.
1999		Disend ‘Afterword’ in Black You Can’t Win (2000) 323: Jack remained a ‘Johnson’, true to the code, even at death’s door.