Russian prosecutors seem confident about their case against Sergei Akhmetov. The evidence includes photos and footage they say show him at an antigovernment protest in Moscow in 2013.
But Akhmetov and his backers say there's just one problem: the man in the images is not him.
They say that Akhmetov, a St. Petersburg architect who is accused of tearing off a policeman's epaulets at the protest and has been in pretrial detention since November, did not attend the demonstration -- and had not been in Moscow since 2011. The man in photos and footage looks something like Akhmetov but is a different person altogether, they contend.
Charged with using force against an officer, Akhmetov could be sentenced to five years in prison if convicted. A trial date has not been announced, but Ekho Moskvy radio and other Russian media reported on May 19 that a court had extended his term in custody until August 10.
The charges against Akhmetov involve a protest on July 18, 2013, in support of Kremlin critic Aleksei Navalny, who had just been convicted of fraud and embezzlement in a politically charged trial. A criminal probe against an unidentified protester who allegedly "grabbed a police officer and ripped off an epaulet from his uniform and ran away" was opened two days after the demonstration.
No arrest was made in connection with the incident until police detained Akhmetov on November 21, 2015, upon his return from a business trip to Germany. He was taken to Moscow, where he was formally charged and sent to the Butyrka detention facility.
Defense lawyer Gadzhi Aliyev says that Russian investigators zeroed in on Akhmetov after looking at the profiles of people who had indicated on Facebook that they planned to attend the rally in support of Navalny. He says Akhmetov had clicked a box registering plans to attend, but did so out of solidarity and did not actually go to the protest.
"They checked his account -- his photographs look like that person, and that's it," he told RFE/RL's Russian Service.
Photographs of the protester police say grabbed the officer's epaulets depict a man wearing a baseball cap and sunglasses who bears some resemblance to Akhmetov, particularly from afar. However, close-ups appear to show that his features, such as his ears and nose, differ from Akhmetov's.
Aliyev also says investigators have been unable to prove that Akhmetov was in Moscow when the rally took place, and that the defense has provided evidence that he was at home in St. Petersburg, some 700 kilometers away, late on the previous day.
"There is no record of any plane, bus, or train ticket, and he doesn't have a driving license," Aliyev said.
Prominent Russian human rights group Memorial has designated Akhmetov a political prisoner. "The prosecution of Sergei Akhmetov, obviously, is an extension of the campaign against Aleksei Navalny and his supporters, and in general, is a campaign of pressure on society that has been expanded in order to prevent citizens from participating in mass street events and protests," it said on April 22.
Russia has used restrictive legislation and force on the streets to tighten control and discourage public protests since Vladimir Putin returned to the Kremlin for a third presidential term in 2012.
Akhmetov's supporters have set up a website calling for his release. It describes him as "simply an architect' and "not an activist at all."