Michael Angel Rosa was a 29-year-old Hispanic/Latino undercover narcotics officer in Rock Springs, Wyoming, killed in the early hours of July 15, 1978. He was shot at close range in or beside an unmarked police vehicle outside the Silver Dollar Bar. Online accounts describe him as a Marine veteran and a relatively new member of the Rock Springs Police Department who had been operating undercover for only months.

The principal suspect was Edward Lee Cantrell, the city’s public safety director, who was accused of shooting Rosa during a confrontation while other officers were present in the vehicle. Rosa’s death drew larger attention because it occurred amid allegations of vice, corruption, and political protection in a boomtown; some reports said Rosa was about to testify before a state grand jury about corruption he had witnessed. The Wyoming Division of Criminal Investigation handled the case, Cantrell was charged with first-degree murder after a lengthy preliminary hearing, and the case was moved to trial and tried after a change of venue.

Famed Wyoming lawyer Gerry Spence defended Cantrell; the defense argued self-defense and the jury returned a not-guilty verdict after a short deliberation. The criminal trial ended without a conviction, and Rosa’s widow later pursued civil litigation. Does anyone have memories of Rosa, the Silver Dollar Bar that night, or the atmosphere in Rock Springs in 1978?