"Based on what was going on at the time, I knew about the L.A. gang problem," he said. Utah gang suspects were "telling us they were Crips from California."

Stallworth said of his work in Utah, it's his investigation of gangs that he's most proud of.

"It's had a lasting impact, first and foremost, on law enforcement," he said.

Wes McBride, president of the California Gang Investigators Association and retired from the Los Angeles County Sheriff's Department, said about 15 years ago he "heard about this guy in Salt Lake who was becoming an expert" in gangsta rap music. So, he invited Stallworth to speak on the topic. It was the first of a series of lectures Stallworth gave on street-gang culture.

"I don't know that any of us ever listened to it," McBride said. "Where he was instrumental with us was pointing out to listen to the words, to listen to what these gangsters were saying."

The two both testified in a 1993 homicide in which a Texas state trooper was killed by a 19-year-old gang member, McBride said. Stallworth was the expert witness on the connection between gangsta rap and gang culture in the case, McBride recalled.

Leticia Medina, executive director of Utah Issues, said she started working with Stallworth on gangs in the late 1980s, when the first Metro Gang Unit was under development. She was a youth corrections provider at the time.

"He was very interested in what my perspectives were," she said. "I learned from him as much as I hope he learned from me.

"Law enforcement is not something that I grew up trusting. I had an opportunity to deal with a cop and see his world," she said.

At the time, Medina said, law enforcement wasn't involved in the community.

"They started the Metro Gang Unit, and everyone knew who the gang unit was," she said. "One key that Ron worked on was getting to know the community and community leaders. . . . Law enforcement needed to be trained in cultural competence and gang culture."

Stallworth has self-published four books on gang culture and has testified before Congress on gangs and violence. He also served as the state's first gang-intelligence coordinator.

In 1994, he was selected by the U.S. Justice Department's National Drug Intelligence Center to participate in a national street-gang symposium, the results of which were presented to the U.S. attorney general.

Now that he's retired, Stallworth plans to remain active, politically and otherwise.

Stallworth is chairman of the Black Advisory Council and serves on Layton's Parks and Recreation Commission and Planning Commission.