The 40-year-old walked out of a Pskov courtroom a free woman after the judge found her guilty and ordered her to pay a fine of 500,000 rubles ($6,950).
Prokopyeva works for the Russian service of the US-funded Radio Free Europe/Radio Liberty (RFE/RL) as a freelance contributor.
A Russian journalist avoided a prison sentence on Monday but was given a $7,000 fine for “justifying terrorism” in a controversial case that sparked an outcry at home and abroad.
Svetlana Prokopyeva, who is based in the northwestern city of Pskov, was charged with publicly justifying terrorism over a column she wrote about a bombing attack that targeted the FSB security service in the north of the country in 2018.
Prosecutors had asked the judge to jail Prokopyeva for six years and ban her from working in journalism for four years on the charges that carry a maximum sentence of seven years.
As the judge read out the verdict, supporters in the courtroom – many of whom had arrived from Moscow – shouted “shame” and “she is not guilty.”
Standing on the steps of the court building holding a large bouquet of flowers, Prokopyeva thanked her allies for their support and vowed to appeal the decision.
“The biggest success is that I was not forbidden from working in my profession,” she told the crowd, sporting a T-shirt that said “We will not shut up”.
Yulia Galyamina, a Moscow deputy in the opposition Yabloko party who described the verdict as “unfair,” tweeted that 10 percent of Prokopyeva’s fine was already collected outside the courtroom.
The journalist’s case has its origins in a November 2018 bombing carried out by a 17-year-old anarchist who blew himself up in a Federal Security Service (FSB) building in Arkhangelsk in northern Russia.
In her commentary, published by the Pskov affiliate of the Echo of Moscow radio station, Prokopyeva linked the teenager’s suicide bombing to the political climate under President Vladimir Putin.
Prokopyeva said she was freed thanks to public pressure.
In a statement published by the Memorial rights group, dozens of human rights defenders denounced the case as “openly political” with the goal of “intimidating Russian journalists”.
“A journalist is entitled to freely spread information not only on events but also on ideas,” they said.
International press advocacy group Reporters Without Borders said it was “relieved” by the ruling and welcomed “the mobilisation in support of the journalist.”
Human Rights Watch said the ruling “creates another dangerous precedent, with a journalist found guilty of a terrorism offence for normal journalistic work”.
“The authorities should immediately and unconditionally vacate her politically motivated conviction,” the watchdog said.
More than 30 prominent Russian journalists spoke out in support of Prokopyeva this month, and more than a dozen of her supporters were briefly detained at a picket last week.
Speaking to reporters after the sentencing, Kremlin spokesman Dmitry Peskov denied the case against Prokopyeva had fuelled public mistrust in Russia’s legal system.
“I see no grounds for that,” he said.
The case comes amid growing concerns over press freedom in Russia where reporters and news organisations face increasing pressure from the authorities.
The arrest of investigative reporter Ivan Golunov on trumped-up drug charges last year sparked an unprecedented public backlash and coordinated media campagin that eventually forced his relase.
Last week, a journalist in the second city of Saint Petersburg was hospitalised with a broken arm following a confrontation with police in a polling station during a nationwide vote on controversial reforms to the constitution that allow Putin to extend his rule until 2036.
Senior editors at Russia’s most influential business newspaper Vedomosti quit last month in protest against what they said was pro-Kremlin censorship.