Sign up for the daily CJR newsletter . In February, the San Antonio Express-News broke a story that quickly became national news: Tony Gonzales, a Republican congressman from Texas, had an affair with Regina Santos-Aviles, an aide who died by suicide after setting herself on fire. The fallout was significant. Gonzales initially denied the relationship. Last month, he admitted to it and dropped his reelection bid. The story had been months in the making. After Santos-Aviles died, in September, Bayliss Wagner and Nancy M. Preyor Johnson , a pair of Express-News reporters, heard rumors of the affair but could not immediately confirm them. What followed was the patient, persistent work that is the foundation of great local journalism: earning trust in the community, building sources, and pursuing every lead. “It’s frustrating at the beginning, because it was difficult to get information,” Preyor Johson told me when I spoke to the duo this week. “It’s no secret that journalists are not trusted, right?…