MOSCOW – The first of 19 defendants being tried for participating in a massive rally against President Vladimir Putin's return to the Kremlin that turned violent pleaded guilty on Friday and was sentenced to 4 1/2 years in prison.
The cases are seen as litmus test about whether the government plans to continue a crackdown on dissent.
None of the other defendants have pleaded guilty and they could receive longer prison terms if convicted.
The May protest was part of a series of anti-Putin rallies that erupted across Russia after fraud-plagued parliamentary elections. The demonstrations drew tens of thousands of people in the largest show of discontent in the country since the 1991 Soviet collapse.
In Zamoskvoretsky district court in Moscow, 36-year-old gym owner Maxim Luzyanin pleaded guilty on Friday to assaulting police and pelting them with pieces of asphalt when scuffles broke out during the May opposition rally in central Moscow. He was given a 4 1/2 year sentence.
None of the 18 other defendants charged with participating in the protest violence have pleaded guilty.
Opposition leaders said police provoked the violence and called Luzyanin's sentencing part of a Kremlin-orchestrated persecution of government critics.
"They'll give the others eight (years) now," Alexei Navalny, a charismatic anti-corruption activist and the protest movement's semi-official leader, tweeted.
During Luzyanin's trial, prosecutors had asked for 6 1/2 years of the maximum sentence of 8 years.
Judge Andrei Fedin said the court decided to give Luzyanin a shorter sentence for several reasons: his guilty plea, his testimony to investigators against other defendants, and his 15-year-old son and dependent mother.
Lawyers and opposition leaders had expected Luzyanin -- who was already under a suspended sentence for extortion -- to get a shorter sentence after cooperating with prosecutors.
Luzyanin had requested an expedited trial, which meant he could receive no more than two-thirds of the maximum sentence and could not challenge evidence.
But afterward his lawyer, Sergei Shushpanov, said his client would appeal his sentence.
Pavel Chikov of the Agora human rights lawyer association, which represents several of the 18 other defendants, said Luzyanin's sentence showed prosecutors "definitely want everyone in prison for a long time in order to frighten the rest of the activists."
Chikov said, "This sends a clear message: Protesters will believe they will get a long sentence just for protesting Putin."
Luzyanin's admission to participating in riots could make it easier to convict the others, whose lawyers have insisted the rioting was spontaneous, not preplanned.
Those defendants also could be held responsible for damage to asphalt in a square where the violence took place, which the court has estimated at $900,000.
Previous anti-Putin rallies had been peaceful. Crowds carefully kept to agreed-upon meeting-places and routes, even making a point of thanking police who stood guard in vast numbers, but did not interfere.
Scuffles broke out at the May protest after police blocked demonstrators from proceeding along the agreed route, creating a bottleneck. Some frustrated protesters attempted to break out from the "kettle" and made for the Kremlin.
Club-wielding officers wearing helmets seized demonstrators and hauled them to police vehicles, dragging some by the hair, others by the neck. Several protesters were injured, including people with blood streaming down their faces and bruises from police truncheons across their backs.
The trials of the remaining 18 defendants are scheduled to start in March, when the ongoing investigation is scheduled to end. Hundreds of investigators have interviewed thousands of witnesses, Russian media reported.