TV news stations and Russian online sites broadcast grainy security footage of the man entering the subway at Sennaya Ploshchad, just minutes before a blast on a train traveling from the station killed 14 and wounded dozens more.
Except he wasn't the terrorist. It was Ilyas Nikitin, a truck driver from provincial Russia, a former army captain who fought Islamic separatists as a Russian officer in Chechnya and later converted to Islam.
State-run TV quickly corrected the mistake. But just that short exposure has already cost Nikitin dearly, subjecting him to public suspicion and nearly getting him fired.
"This case has deeply complicated my life," Nikitin told a Russian news portal called Islam News this week. Since the bombing, he said, he had been pulled off a flight because other passengers recognized him as the suspected bomber and was told he could lose his job because of the investigation. He asked that reporters stop hounding him and his family.
The story is a cautionary tale of the speed with which digital sleuthing, instant Twitter news updates, and racial profiling can yield devastating consequences for their targets. For journalists, the Internet has proven to be a quick source of vetted information and expert collaboration - but it also has the potential to destroy lives.
Nikitin's story is not isolated, nor is it unique to Russia. In an infamous case of mistaken identity, the New York Post published photographs of two men carrying bags at the 2013 Boston Marathon, where bomb blasts killed three and wounded more than 160. The headline above the photograph on the front page was "Bag Men," insinuating that the bags contained explosives and the men were sought by law enforcement. The men were not, in fact, behind the attack. The paper was hit with a defamation lawsuit and settled for an undisclosed amount in 2014.
Just last month, Internet sleuths also decided that Abu Izzadeen, a radical British cleric, was behind the attacks on the Westminster bridge in London, which left five dead including the attacker. The problem with that theory? Izzadeen was sitting in a jail cell at the time.
Nikitin was one of two men incorrectly accused of the bombing just hours after the St. Petersburg attack. The other, a Kazakh-born, straight-A student at a local economic university, was killed in the blast.
Nikitin has sought to clear his name. As soon as he heard in the hours after the attack that his photograph was being broadcast nationwide, he turned himself in.
The police acted professionally, he said. "The police accepted my explanation and all suspicions about me were dropped," he told Islam News.
But not everyone got the message, and when he boarded a flight to Ufa, the capital of Nikitin's native Bashkortistan region, other passengers recognized him as the suspected bomber.
"I wasn't able to fly home - the other passengers refused to fly with me on the same plane," he said.
Nikitin could not immediately be reached for contact, but his account was confirmed by a representative for Rossiya airlines to the RIA Novosti news agency.
"Passengers told the crew that there was a man on board who looked exactly like the man being sought for the St. Petersburg bomb," the spokesman said. "The man was taken off the plane and handed to police."
Nikitin said he was let go after a cursory search, but missed the flight and decided to travel further across Russia by minibus.
That wasn't the end of Nikitin's story. Later, he told the interviewer, his employer called him to tell him he had lost his job as a long-distance trucker.
"Today my employer in Nizhnevartovsk," a Russian city, "informed me that I was fired, citing a request by the regional investigative committee," he said in the interview.
Investigative committee officials denied they had sought Nikitin's firing, Znak.com, a respected Siberian news portal, reported.
In an update on Thursday, he told Islam New that he would be allowed to return to work.
The final problem, Nikitin said, was with the journalists themselves, who had made him a prime subject of attention.
"The same reporters who were calling me a terrorist before are now stalking me, my loved ones and friends," he said in the interview earlier this week. "Please don't chase after me and let me live my own life."
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)