A difficult reality of photojournalism is that photographers often define their careers by covering conflict. Egyptian photojournalist Mosa’ab Elshamy is the latest example. Elshamy began photographing as a citizen journalist during the Arab Spring protests in Egypt in 2011, when he documented demonstrations against then-President Hosni Mubarak in Cairo’s Tahrir Square. Two and a half-years later, he’s made the transition from being an amateur to being a photojournalist who is watched by top photo editors and a nearly 40,000-strong Twitter following.

Elshamy’s work in Egypt, and from Gaza during the 2012 war there, has been published by the likes of The Economist and Harper’s among others, and he’s won awards in the Egypt International Photography Contest and Arab Union of Photographers competition. Yet during the last few weeks his photos of Egypt’s descent into violence, particularly his images of the clearing of a pro-Morsi sit-in at Rabaa at the end of July, have earned him the cover of The New York Times and bylines for TIME International and AlJazeera English, among other publications.

Patrick Witty, international picture editor of TIME, says he first heard about Elshamy’s work on Twitter at the end of July. “After the massacre at Rabaa Square on July 27, someone I follow tweeted about a picture he made,” Witty told PDN in an email. “I tracked it back to his Flickr account and reached out to him.”

A series of Elshamy’s images from Rabaa were published in TIME International, and on the TIME Lightbox photojournalism blog just two days later. “I was speechless when I saw his photographs from Rabaa—the intensity, the tragedy—they needed to be seen,” Witty says.

In an interview published yesterday on the website of The Washington Post, Elshamy spoke about learning to react and shoot bursts of pictures quickly. He’s learned, he told the Post‘s Max Fisher, to “appreciate how significant events really end up taking seconds…. I have full sequences, and sometimes it starts with somebody standing, but in the sixth or seventh photo, he’s got a bullet through his head, and it all took less than a second.

“The consequences of that moment, of this guy getting shot or avoiding a bullet that killed someone else—it’s a very significant thing, and more often that’s becoming lost. I try to focus on that in my pictures, I try to include as few people as possible; just a man sitting with a killed friend of his, or a mother mourning next to a daughter. It’s a very individual act, one person killing another person.”

Witty says that, even though Elshamy was a protester with a camera during the Arab Spring before making the transition to professional, he has had no worries about Elshamy’s journalistic integrity. “I see a tremendous amount of compassion and honesty in his photos, even in his tweets,” Witty says. “I sense no agenda other than to document the tragedy around him.”

Witty believes Elshamy has “found his calling” as a photojournalist, and says he possesses “a natural eye and a strong esthetic.”

“I think we will see more photojournalists begin their careers this way,” Witty adds. “I also think his rapid rise is a reflection of the time in which we live. With Twitter, Facebook, Instagram and Tumblr, it’s easier than ever to discover talented photographers. And easier than ever for them to spread their work. All it takes is one tweet.”