The "rule" in this case is that the legacy media labors mightily to avoid associating immigration and immigrants with any malign behavior, while highlighting any victimization of immigrants. This has been a long-running theme at VDARE.com (although unlike the parallel concept of "not reporting race," it hasn't yet earned its own tag here).
For example, referencing a Daily Beast column this April, in “San Diego Couple Enslaved Their Maid” A Lie–Why Not “Iraqi Immigrant Couple Enslaved San Diego Woman”?, editor James Fulford noted that, "In many, many stories like this, the victim appears in the headlines as an immigrant, and the immigrant slavers appear as a 'San Diego' or 'Long Island' couple." (For this case, the immigrant status of the perps was obscured—in keeping with the rule—but the immigrant sob-story involved was apparently overlooked.)
In her 2015 book ¡Adios America!: The Left's Plan To Turn Our Country Into A Third World Hellhole, Ann Coulter devoted an entire chapter to the 'not-reporting-immigration' phenomenon, with chapter title "Public Warned To Be On Lookout For Man." The rule also plays a role in her four between-chapter interludes jointly titled "Spot The Immigrant!"
So it was startling to see the dominant headline "Immigrant wanted in NY-area bombings captured in shootout" printed in the Bozeman, Montana daily newspaper on September 20. Of course, our Chronicle is a small paper, relying on wire services such as the Associated Press [AP] for coverage beyond the local area. The question then becomes, "Did a non-politically-correct Bozeman editor write that headline?"
Nope, the headline goes with this AP story, having also appeared in many smaller cities around the country such as Joplin, Missouri; Gloversville, New York; Lubbock, Texas; and Charleston, South Carolina. Judging by an AP-stylebook diktat in April 2013, it's a good guess that some rookie editor who hasn't yet heard the word wrote a terrorism-related headline that started with the word "immigrant." Man bites dog!