Trayvon Martin, an unarmed 17-year-old, was fatally shot on Feb. 26 in Sanford, Fla. The next day his death was a top story on the Fox-affiliated television station in Orlando, the closest big city to Sanford. Within a week it was being covered by newspapers around the state.

But it took several weeks before the rest of the country found out.

It was not until mid-March, after word spread on Facebook and Twitter, that the shooting of Trayvon by George Zimmerman, 28, was widely reported by the national news media, highlighting the complex ways that news does and does not travel in the Internet age.

That Trayvon’s name is known at all is a testament to his family, which hired a tenacious lawyer to pursue legal action and to persuade sympathetic members of the news media to cover the case. Just as important, family members were willing to answer the same painful questions over and over at news conferences and in TV interviews.

Notably, many of the national media figures who initially devoted time to the shooting are black, which some journalists and advocacy groups say attests to the need for diversity in newsrooms. The racial and ethnic makeup of newsrooms, where minorities tend to be underrepresented relative to the general population, has long been a source of tension for the news industry.