Newsrooms demonstrated remarkable caution this week and avoided speculation about the motives of Mohammad Youssuf Abdulazeez, 24, who went on a shooting spree in Chattanooga, Tenn., killing four U.S. Marines and injuring several more.

The same cannot be said, however, for how the press reacted in February when three Arab-American teens were shot and killed in Chapel Hill, N.C., over what turned out to be a parking dispute. In that case, many in media appeared to suggest that the motive was anti-Muslim sentiment.