During the 1980s, Rosenfeld's reports for the San Francisco Examiner revealed that poor medical care in California prisons had led to inmate injuries and costly legal settlements.
In other articles, Rosenfeld reported alleged links between contra rebels seeking to overthrow the Sandinista government of Nicaragua and a cocaine smuggling ring in the so-called Frogman Case.
The articles led to congressional inquiries, and a subsequent report released by the U.S. Department of Justice's Inspector General found that the prosecutors had returned the money at the request of the CIA.
In the 1990s, Rosenfeld's series, Anatomy of a Killing, revealed a systemic breakdown in the San Francisco Police Department's investigation into an officer's fatal shooting of a young man in the back.
In 2002, the Chronicle published Rosenfeld's article, The Campus Files, which was based on FBI records showing that the bureau had engaged in unlawful surveillance and harassment of students, professors and administrators at the University of California in the 1960s.