A dramatic image of the assassination of Russia’s ambassador to Turkey was named the Photo of the Year in the 2017 World Press Photo contest.

The photo was taken in December during a routine assignment at a photo exhibition that Burhan Ozbilici, an Associated Press photographer, decided to attend at the last moment simply because it was on his way home.

He arrived during Ambassador Andrey G. Karlov’s speech, and within moments a 22-year-old off-duty police officer, Mevlut Mert Altintas, opened fire. Although Mr. Ozbilici was no more than 15 feet from the gunman, he did not run.

Image of Turkish assassin wins 2017 World Press Photo award

“I was afraid, but I did not panic,” Mr. Ozbilici, 59, said in a phone interview. “I’m a journalist and I had to stand and do my job even if I got hit or killed. At that moment I tried to represent not just A.P. but all good independent journalists.”

Lars Boering, World Press Photo’s managing director, said that while some winning photos in recent years “were more poetic and open to interpretation,” Mr. Ozbilici’s image fit well into the organization’s 63-year tradition. “The photo is a strong visual representation,” he said, “of a very brutal event by a brave photographer.”

juror, Mary F. Calvert, emphasized that the organization was “rewarding the photographer, not rewarding the crime.” If anything, she said, she thinks the image “embodies the hate and desperation in our world today” and will have enduring historical value.

“It’s our job as photographers to bear witness, sometimes showing things to people that aren’t pretty,” Ms. Calvert said. “It’s up to the viewers to make choices in how they respond.”