Upon graduation Montgomery was hired by the Nevada State Journal, but left the Journal two years later to pursue work in other media. He returned to journalism in 1938, joining the Reno Evening Gazette, where he first worked as an editor. Montgomery served in the Marine Corps during World War II (1942–45).
After the war, Montgomery went to work for the San Francisco Examiner, where he stayed until his retirement in 1975. During his time at the Examiner, Montgomery became involved in two murder trials. He found the body of Stephanie Bryan in May 1955. Burton Abbott was later sentenced to death for her murder. That same year, Montgomery reported on Barbara Graham's execution. His coverage of the Graham case was adapted into the film I Want to Live! (1958).
In 1960, 22-year-old Robert Meisenbach was acquitted after being charged with provoking a confrontation between police and students protesting the House Un-American Activities Committee hearings in San Francisco. The charge was largely supported by a story written by Montgomery, which said Meisenbach had clubbed the officer with a baton. Montgomery never testified, after admitting before the trial that his story was false. Montgomery, a longtime water carrier for the FBI, had published it anyway. An 18-page booklet, "Communist Target — Youth: Communist Infiltration and Agitation Tactics.", signed by J. Edgar Hoover and released to news outlets across the country, which said Communists had orchestrated the protests and used "mob psychology" to incite the students, portrayed as gullible dupes, was based on Montgomery's false report.
Montgomery died of pneumonia in San Francisco in 1992.
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- Brennan, Elizabeth A.; Clarage, Elizabeth C. (1999). Who's who of Pulitzer Prize Winners. Greenwood Publishing Group. p. 387. ISBN 9781573561112.
- "How red-baiting crusade collapsed in SF courtroom in 1960". SFChronicle.com. 2017-02-04. Retrieved 2019-11-03.
- "Remembering Friends". University of Nevada, Reno. 2007. Helene Montgomery ’35. Retrieved April 29, 2015.
- "Helene Montgomery". San Francisco Chronicle. May 15, 2007. Retrieved January 29, 2016.
- "Ed Montgomery; Award-Winning Journalist". Los Angeles Times. April 11, 1992. Retrieved April 28, 2015.