KIEV — Yevgenia Zakrevskaya, an attorney here in the Ukrainian capital, is one of the strongest liberal voices in the country, fighting hard for democratic values and the rule of law. Persistent, punctilious, and stubborn, the 36-year-old Zakrevskaya has pieced together a mosaic of evidence proving that the entire Ukraine state system from top to bottom was responsible for the tragic events in February 2014 when more than 100 protesters were killed in the streets of Kiev.

Representing 20 victims and their family members, Zakrevskaya wants to send a strong message to Moscow and Washington, as well as to all Ukrainian officials: everyone complicit in ordering the mass murder of unarmed protesters in Maidan Square must be prosecuted and punished, even if it takes years—and even if the list of suspects comes to include people like former Donald Trump campaign chief Paul Manafort or, indeed, people protected by Russian President Vladimir Putin.

Right now, Ukraine is watching the historic public trial of five former Kiev policemen. The men in the dock are members of “the Black Unit,” Kiev’s feared Berkut police, suspected of murdering 48 people and injuring up to 80 participants in the Maidan revolution on Feb. 20, 2014.

For three years Zakrevskaya has been collecting photo and video evidence, as well as physical evidence such as bullets and shells from around the square to prove not only that this police unit fired at the protesters but that they did so under orders.

The bullets Zakrevskaya, her colleagues and clients have discovered are not made of plastic; the video footage depicted men in uniforms shooting guns at protesters in Kiev.

“This trial could be compared to the Bloody Sunday trial in Ireland or to the court hearing against the murderers of protesters in Lithuania in 1991,” Zakrevskaya tells The Daily Beast.

Many in Ukraine believe that former President Yanukovych was responsible for ordering the mass murder of Maidan revolutionaries and that the entire system of power has to be cleansed and reformed.

Others say that it is enough to see a few policemen on trial, that the law enforcement agencies should not go after all officials on all levels, even if some involved in suppressing the revolutionary movement might be still working in Ukraine’s state institutions.

Zakrevskaya insists that all witnesses deserve attention. It’s in that context that the name of Paul Manafort comes up, since the American political operator was an advisor both for Yanukovych and eventually U.S. presidential candidate Donald Trump, Zakrevskaya told The Daily Beast.

Beginning in 2005, Manafort was advising Yanukovych and his Russia-backed Party of Regions as well as the party’s biggest sponsor, Ukrainian oligarch Renat Akhmetov.Even after the violent events of February 2014 and Yanukovych’s shameful escape to Russia, Manafort returned to Ukraine to reshape the former ruling Party of Regions into the Oppo Bloc.

Manafort’s tenure as Trump’s campaign chief ended after reports last summer that he received millions of dollars in cash payments, allegedly stolen from Ukrainian tax payers.

It’s been reported as well that Manafort’s daughters felt concerned about their father’s interactions with former President Yanukovych.

What appear to be hacked text messages among Manafort’s daughters include this sinister judgment by Andrea Manafort: “Don’t fool yourself. That money we have is blood money.”

Manafort has not yet responded to queries from The Daily Beast about the allegations in Ukraine or his daugthers’ alleged text messages.

The key question for Ukraine is whether Manafort was advising Yanukovych during the days of violence in late February 2014, at precisely the time when the Berkut police fired machine guns at unarmed people on Kiev’s Independence Square.

Zakrevskaya said she'd welcome any efforts by Manafort's daughters and the U.S. law enforcement that might help Ukraine find out the truth. "This trial could be a lesson for the entire world," she said.

Yanukovych is exiled in Russia, but in November, Zakrevskaya had a chance to him about the killings, via videoconference. “The former president said that it was not police but some ‘radicals’ who had shot people dead in Kiev, ” Zakrevskaya said.

One of Zakrevskaya’s clients, Vladimir Bondarchuk, is looking for justice in the case of his father, Sergei Bondarchuk, a schoolteacher from Starokonstantinovka who was shot dead on Maidan Square. In the dramatic video Vladimir presented to the court as evidence, his father can be seen carrying a wounded protester, seconds before he was fatally wounded himself.

“We found a video of a police officer in a black uniform with a yellow ribbon around his arm firing an AK-47 assault rifle in the direction of my father,” Bondarchuk told The Daily Beast. “One of the bullets hit my father’s body when he and his friends were carrying another fatally injured protester towards a shelter without paying attention to the rain of bullets fired at them,” Bondarchuk said. His voice cracked as he spoke, even now, three years after the violence.

Both Zakrevskaya and her client struggle say they are at a loss to understand how officials sworn to protect the nation could shoot guns at people carrying a wounded man.

Most of the Berkut policemen who were fighting Maidan’s revolutionaries managed to escape to Russia in February,2014. The officers on trial today are accused, specifically, of killing 48 participants in the uprising on Institustaya Street. They say they are innocent and insist that if they fired it was in response to revolutionaries attacking them.

Zakrevskaya does not believe that they are telling the truth: “In the videos we have studied it is evident that the riot policemen fired at the protesters from a position behind a concrete barricade, which means the unit was under a full control,” Zakrevskaya said. “This awful crime is now being considered by the International Criminal Court.”

Ukrainian legal expert Mikhail Zhernakov believes that the trial against former policemen is hugely important for Ukraine today.

“All Mr. Yanukovych’s allies, supporters of the former regime should be questioned on this case, as potentially responsible in mass killings during Maidan protests; including, if the facts get proved, Mr. Manafort,” Mikhail Zhernakov told The Daily Beast. “By recognizing the killings as the crime against humanity, and that is how many in Ukraine see the shootings, the International Criminal Court would help the progress of this historical process for our country.”

Given Manafort’s important connection to President Trump, discovering the truth about Manafort’s role in February 2014 could have historical significance for the United States as well.