"I heard shots, very loud -- bam bam bam," Burhan Ozbilici told CNN.
"The people standing in front they disappeared. They threw them(selves) on the floor. They were trying to hide, to take shelter. I was shocked ... afraid ... not panicked."
Ozbilici hadn't planned to attend the new photo exhibition in the Turkish capital but made a snap decision to stop in on his way home from the office. With Russia-Turkey relations
appearing to thaw in recent weeks, the AP photographer thought some images of Karlov
speaking at the gallery might be useful in the near future.
"He was very soft, calm, a very natural man. Not a diplomat we usually see."
'I have a responsibility to record the event'
But in the blink of an eye, the tranquil scene in the gallery was shattered. Gunshots rang out and people scattered as a blind panic hung in the air.
Ozbilici scrambled to the back of the showroom, finding partial refuge behind a wall. He watched as the gunman walked around the ambassador's body, describing him as agitated as he ripped several of the photographs on display off of the wall.
"In difficult situations, I'm calm. I have a responsibility to record the event," he told CNN. "The ambassador was lying on the ground -- not moving. And the (shooter) was making (a) politically-motivated speech.
He added: "Some people were screaming, crying, so i could not hear well."
"I was, of course, fearful and knew of the danger if the gunman turned toward me," he wrote earlier on APNews.com
. "But I advanced a little and photographed the man as he hectored his desperate, captive audience."
"This is what I was thinking: 'I'm here. Even if I get hit and injured, or killed, I'm a journalist. I have to do my work. I could run away without making any photos ... But I wouldn't have a proper answer if people later ask me: 'Why didn't you take pictures?'"
He added: "I even thought about friends and colleagues who have died while taking photographs in conflict zones over the years."
All the while, Ozbilici continued working, documenting the political assassination from a perspective that would lead news outlets across the globe within hours.
"As my mind raced, I saw that the man was agitated -- and yet, he was, strangely, in control of himself. He shouted at everyone to stand back. Security guards ordered us to vacate the hall and we left."
Ozbilici told CNN it wasn't until later when he began editing his photos that he truly comprehended the premeditation behind the shooter's calculated attack.
"When I got back to edit my photos, I saw (in) my two very first photos (that) the gunman was standing behind ambassador ... like he was part of embassy staff or somebody from the art gallery -- very calm.
"I felt very bad to see an innocent man lying on the ground... lifeless."
Hailed as a 'hero'
Within minutes of their release, Ozbilici's photographs spread like wildfire through social networks.
Photographers and journalists the world over praised his composure in the face of terror.
"What bravery AP's @BurhanOzbilici showed to capture those photos. Wire staff very often unsung and very often the heroes of this trade," wrote Barry Malone
, online editor at Al Jazeera English.
Journalist Bronwen Dickey wrote on Twitter
: "Before I die, may I know one-hundreth of @BurhanOzbilici's courage."
of The New York Times added: "Awed by the courage of the photographer who captured this terrifying shot. (Credit: Burhan Ozbilici/AP)."