It wasn't until the mid-1960s that a group of ____________ emerged to explore criminality systematically as a matter of definition.

Mid-1960s

A period characterized by significant social, political, and cultural changes worldwide, roughly between 1964 and 1966.

Criminality

Involvement in criminal activities or the qualities that characterize a criminal.

Systematically

In a methodical and organized manner, often following a specific system, plan, or structure.