The nine-year-old girl headed to the soccer stadium with her friends on a rainy Monday to join thousands of people protesting Guinea’s junta government, calling for democracy. But the singing and dancing turned to mayhem when security forces opened fire, Djenabou Bah later recounted. She tried to run but soldiers caught her. They repeatedly stabbed her with bayonets, then raped her.

“For 13 years, nothing has been done,” said Bah, now 22, her eyes blank and the scars of knife wounds still visible on her hands and neck.

After years of delay, this West African country has begun trying the officials – including former president Moussa Dadis Camara – allegedly responsible for the carnage at the stadium on September 28, 2009, when security forces killed more than 150 civilians and raped more than 100 women, according to a United Nations commission, then tried to cover it up.

Human rights experts say the trial, which began on Wednesday, is historic because governments rarely try their own leaders in domestic courts for atrocities of such magnitude. Victims have praised the proceeding as a chance for long-awaited justice.

“Now is the first time I have some hope,” said Bah, who says she is ready to forgive despite the horrors she experienced and those she witnessed – including members of the presidential guard mowing down protesters as they knelt to pray. But for many in Conakry, hopes of righting past injustices are dampened by the reality of the present.

Since last year, Guinea’s government has been led by a new military junta, which has banned public demonstrations and dissolved the coalition of civil society groups that served as its main opposition. The junta, helmed by Col Mamady Doumbouya, has faced widespread international condemnation and sanctions for failing to establish a timeline for democratic elections.

But Doumbouya has also been consistent in his commitment to holding a trial. Former president Alpha Condé, who Doumbouya ousted in a bloodless coup last year, had avoided doing so during more than a decade in power, despite strong pressure from domestic and international human rights groups to act. The International Criminal Court began examining the case in 2009 and will continue to closely follow the proceedings, ICC prosecutor Karim Khan said.

“These crimes were among the most brutal in Guinea’s history, the kind that shocks the conscious,” said Elise Keppler, associate international justice director at Human Rights Watch, which has been documenting the violence since 2009. “Fair credible proceedings are necessary to send a clear message that such crimes cannot be tolerated.”

Ibrahima Diallo, a local activist who has been jailed since July for helping to organize a protest, said he worries the junta’s decision to launch the trial on Wednesday — the 13th anniversary of the massacre — seems to be more about publicity than justice.

“It’s about winning international goodwill,” said Diallo, who was a student leader in the stadium that day, “and justifying their decision to stay in power … I want justice, but my fear is that this is not about real justice.”

Diallo had been living in exile under Condé, who had become increasingly repressive and sparked widespread outrage when he ran for a third term. Diallo returned to Conakry last year after the coup, optimistic about Doumbouya’s stated commitment to democracy. Diallo said any hope vanished as he saw Doumbouya’s government crackdown on dissent, with security forces fatally wounding multiple peaceful protesters and eventually showing up in hoods at Diallo’s house to arrest him. He is now detained at the same Conakry prison as Camara.

Outside the courthouse on Wednesday, a young woman who said she was raped in the stadium waited with clasped hands for the opening. An older woman whose husband’s body was never found clung to the arm of a young man whose father’s dead body was also never recovered. Around the courtyard of the new courthouse, built especially for the trial, were banners with Guinea’s red, yellow and green flag, and signs with hammers and scales of justice declaring: “Justice for all.”

Alphonse Charles Wright, Guinea’s justice minister, promised in a speech outside the courthouse that the trial would be transparent, impartial and safe. The country, he said, would not be afraid to confront its past.

Inside the courtroom, Camara, who had been living in Burkina Faso and returned to Conakry for the trial, sat quietly through opening proceedings along with 10 other top members of his government accused of orchestrating the killing.

Camara and the other defendants have not yet entered pleas. A lawyer for Camara, who has maintained his innocence since the massacre, said he will plead not guilty.

The trial could last more than a year, Wright said, with victims able to personally testify. How the coup in Guinea could raise car prices — or foster better deals for its people

As Asmaou Diallo sat in her Conakry office this week, a framed photo of her son, killed during the massacre, hung on the wall behind her. She said survivors and victims’ families want compensation. They want government recognition of the horrors they endured. And they want the facts finally revealed.

“We want the truth,” said Asmaou Diallo, the president the Association of Victims, Parents and Friends of the Sept. 28 Massacre. “Why? That is what we want to know. Who ordered it?”

She said she is grateful that the government has finally decided to act. But she said she also fears for democracy.

Victims and their families crowded into her organisation’s lobby this week, bringing with them medical records and photographs as they prepared to testify. Among them was Oumar Diallo, a 55-year-old truck driver who said he saw a soldier smash his rifle into the skull of a woman in front of him. When Oumar Diallo raised his arms to shield his own face, the soldier broke them with his rifle.

He said he spent more than a month in the hospital and has not been able to work since, his arms still too mangled. He has received no compensation from the government, relying on his family and charity to help him support his daughters. His hope, he said, is that the trial brings a measure of support.

Saran Cissé, a 43-year-old mother with a quick smile, recalled hearing a few loud “booms,” then seeing those around her begin to fall. A young man who tried to help her escape over a stadium wall was shot in the head. When security forces approached, she begged them to kill her instead of rape her. They did not listen.

In the months that followed, she said, her husband rejected her because of the stigma of assault and tried to keep her from her children. “I have suffered humiliation,” she said, as tears streamed down her face, but added that she was determined to keep telling her story so that the atrocities would never be repeated.

For Bah, who said she was raped and stabbed at age 9, there has been no moving on. She was rejected by the man who had been chosen for her to marry. She has headaches and often struggles to sleep. “I have had no peace,” she said, her voice quiet and her gaze facing downward.

When asked if she would testify at the trial, her eyes for the first time lit up. “Of course,” she said. “I am ready.”

• A Washington Post report