It was a perplexing event, with little in the way of legal closure. Seven years on from a fatal biker shootout in 2015, Mark Binelli explores the details of the event — which started as a brawl between rival “outlaw” motorcycle clubs, the Cossacks and the Bandidos, at a restaurant in Waco, West Texas, which left nine dead and 20 wounded — and the investigation that followed.

The article delves into the methodology of the case’s main investigator, Paul Looney, and a trial-preparation specialist, Roxanne Avery, as well as the event’s cultural significance, described by The New York Times as “what appears to be the largest roundup and mass arrest of bikers in recent American history.”

The aftermath of the deadly brawl, which was preceded by rumblings of an escalating feud, has been the subject of protracted interest: Despite the arrests of 177 bikers — all of whom, regardless of the evidence, were subject to identical felony charges and million-dollar bonds — no one has been convicted.

Binelli explains the root causes of the tensions between the Bandidos and the Cossacks, relays the details of the incident, and considers why it has been so hard to bring the perpetrators to justice.

This story was written by Mark Binelli and recorded by Audm. To hear more audio stories from publications like The New York Times, download Audm for iPhone or Android.

Unlock full access to New York Times podcasts and explore everything from politics to pop culture. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify.