In 1993, then-Senator Daniel Patrick Moynihan published an essay entitled “Defining Deviancy Down,” in which he argued that understanding the shift towards more permissive attitudes regarding crime and violence is crucial to their reduction. Specifically, he asserted that the redefinition of norms around deviant behavior (or “defining deviancy down”) had collectively shaped society in unintended ways, resulting in a desensitization to what might have once been considered shocking. By way of illustration, Moynihan referenced the 1929 St. Valentine’s Day Massacre in Chicago—the notorious gangland execution of seven men committed during the prohibition era. He reminded his readers that those killings had elicited universal public outrage, and then contrasted that reaction with a contemporary example: “On the morning after the close of the [1992] Democratic National Convention in New York City in July,” he wrote, a headline reported “3 Slain in Bronx Apartment, but a Baby is Saved…A mother’s last act was to hide her little girl under the bed.” These were also execution-style killings, but they were greeted with only a barely discernible nod of …