|Police fought with protesters who had set up barricades during last year's riots [EPA]
In a corner of Alla Hovannisian's living room in Yerevan is a small memorial to her son, with religious icons, fresh flowers, and an old school photograph.
Tigran died when he was 23, during civil unrest in the Armenian capital on March 1 last year, violence which shocked and divided this small country.
His mother says that when she first heard that he had been killed, she refused to believe it.
"I said it must be a mistake, it must be someone else's body in the morgue, and my husband went a second time to check," she recalls.
|Alla's son, Tigran, died when he was 23, during civil unrest in the Armenian capital last year
Pitched battles raged into the early hours of the morning after riot police moved in to end more than a week of demonstrations against the results of presidential elections which the opposition claimed were falsified.
The night sky was lit up with tracer bullet fire and flames rose from burning cars as police fired tear gas and fought with protesters who had set up barricades and armed themselves with petrol bombs and metal staves.
Alla's son was one of several people who were shot during the clashes which left eight civilians and two policemen dead, causing the Armenian authorities to impose a state of emergency and send the army onto the streets.
"Tigran was killed with a special weapon, a tear gas gun which only the police have," claims his mother.
"I blame the people who killed him, but most of all I blame the ones who gave the orders to shoot."
As she spoke, her husband sat nearby, quietly crying.
A new report from Human Rights Watch says that the Armenian authorities have prosecuted dozens of opposition members for their alleged involvement in last year's violence, but haven't held the police to account for what the campaign group claims was the "excessive use of force".
More than 50 opposition supporters have already been jailed after what Human Rights Watch alleges have sometimes been "flawed and politically motivated" trials, but no policeman has yet been prosecuted.
"The authorities' response to the March 1 events has been one-sided," said Giorgi Gogia, the author of the Human Rights Watch report.
"The fact that police were themselves under attack at times by no means excuses them for incidents when they used excessive force."
The most high-profile and controversial trial is still under way.
Seven men, including Alexander Arzumanian, the former Armenian foreign minister, and three members of parliament, are being prosecuted for allegedly trying to overthrow the government by force.
Melissa Brown, the former foreign minister's wife, says that it's a "show trial" intended to silence dissent.
"My husband worked at the UN, he worked as foreign minister, he worked in the opposition; now his work is to serve time as a political prisoner and to stand up and show people that the things they’re fighting for are worth fighting for," she says.
Alexander Arzumanian was the campaign manager for the outspoken opposition leader, Levon Ter-Petrossian, who was defeated in last year's disputed presidential elections by the establishment candidate, Serzh Sarkisian.
|Ter-Petrossian and his allies deny trying to overthrow the government [AFP]
Ter-Petrossian had been Armenia's president before, in the 1990s, when he also sent troops onto the streets to quell protests after being accused of rigging an election.
But Melissa Brown insists that her husband and his allies were struggling for freedom and democracy, and will continue to do so even if they're convicted.
"Personally, I think they're heroes, because they're willing to go to jail for their beliefs and to stay in jail for as long as it takes," she says.
The Armenian authorities reject allegations that the trials have been politically motivated and insist that there are no political prisoners in the country.
"A certain group tried to seize power by force, which is a crime," says Sona Truzian, the spokeswoman for the Armenian state prosecutor.
"In any country in the world, political activities have to be carried out within the law.
"It doesn't matter if someone is a politician or an ordinary citizen - if they have broken the law, they have to be brought to justice."
To support its claim that the opposition leaders organised the violence as part of an attempted coup, the prosecution service has released details of witness statements and transcripts of telephone conversations which were intercepted by the security services.
|The government deployed tanks and soldiers on the streets of Yerevan, the capital [EPA]
The surveillance transcripts seen by Al Jazeera appear to show some opposition leaders discussing how to bring more of their supporters to the demonstration just before the deadly clashes, and showing approval of the burning of a police car, but they do not mention any plan to overthrow the government.
The prosecution service, however, insists that the violence was well organised and that opposition activists distributed weapons to use against the police.
Human Rights Watch says that the full picture of what happened a year ago in Yerevan has yet to emerge.
An Armenian parliamentary commission set up to examine the violence hasn't yet published its findings.
Official investigators have admitted that three of the civilian victims were killed by tear gas grenades fired from close range by riot police, but they say they cannot identify which officers were responsible.
Alla, whose son died that night, hopes that the guilty will be punished, but doubts whether the whole truth will ever come out.
"I can imagine what happened, but will it ever be revealed?" she asks. "I don't think so."
Source: Al Jazeera