Kyiv, Ukraine – Years before Russia’s full-scale war in Ukraine began in 2022, Oleksandra Matviichuk and her Center for Civil Liberties, a Kyiv-based human rights group, were already documenting the experiences of Ukrainians captured by Russian soldiers, intelligence operatives and pro-Moscow separatists.

“I personally interviewed hundreds and hundreds of people who survived Russian captivity,” she told Al Jazeera in her office in central Kyiv.

The survivors told her and her colleagues how they’d been beaten, raped and electrocuted. Some had their fingers cut off and nails torn away or drilled in makeshift prisons and concentration camps known as “basements”.

Dozens more were allegedly executed arbitrarily, found dead with evidence of torture on their bodies or are still reported as missing.

According to Matviichuk, these cases were part of the Kremlin’s strategy to eliminate pro-Ukrainian activists and horrify everyone else into submission in each village, town or city Russia seized.

“When Russians occupy a city, they start to deliberately exterminate active people, journalists, priests, artists, teachers, mayors, human rights defenders,” she said.

The Center for Civil Liberties won the 2022 Nobel Peace Prize jointly with the Belarusian activist Ales Bialiatski and Russian organisation Memorial.

‘We’re not historians. We’re lawyers’

When the war began more than two years ago, Matviichuk’s name was found on lists of targets that Russian soldiers carried with them, her staffers and Ukrainian intelligence said.

Even with all her firsthand knowledge, Matviichuk was still shocked by what happened in 2022 in Russia-occupied Ukrainian towns.

In one of them, Bucha outside Kyiv, Russian servicemen shot dead hundreds of civilians, according to witnesses.

“Russians killed them only because they could,” Matviichuk said.

To her, the killings signified a new level of violence – senseless, just for the sake of it, with total impunity and tacit approval from the Kremlin.

Yet, she does not believe in “symmetrical” measures such as extrajudicial killings of Russian war criminals.

As of June, hundreds of the centre’s volunteers and staffers had documented 72,000 alleged war crimes Russian servicemen committed in Ukraine – but their ultimate goal goes far beyond the records.

“We’re not historians. We’re lawyers,” Matviichuk said.

She wants to establish a tribunal for Russian President Vladimir Putin, an international mechanism to bring to justice every cog in Russia’s war machine – servicemen and military, civilian and religious leaders and television personalities who cosy up to the Kremlin.

“There’s a considerable movement for a war crimes tribunal today, and Matviichuk has been central in the work to bring the necessary support for this idea,” Ivar Dale, a senior policy adviser with the Norwegian Helsinki Committee, a rights watchdog, told Al Jazeera.

“She manages to combine grassroots activism with high-level international advocacy,” he said.

Recalling one of Matviichuk’s speeches she witnessed in Berlin, Alisa Ganieva, a dissident Russian author who emigrated after 2022, had nothing but high praise.

“Oleksandra can mesmerise with the sound of her voice, with a thought. She can hit with a rhetoric trick, a logical argument, can inspire empathy and make the European public want to help [Ukraine] through action,” she told Al Jazeera.

Meanwhile, Matviichuk’s colleagues share her dedication and pay little thought to the Nobel Peace Prize the group received in 2022.

“Abroad, they’re like, ‘Oh, you won the Nobel Prize.’ But here, everyone’s focused on the war,” said Alona Maksimenko, 26, the office coordinator who was the first to receive the call from the Norwegian Nobel Committee.

The Nobel, however, helps attract more funds and staffers – even if some have to cross an ocean to join.

One of them is Anna Nazaryk, an Argentinian with Ukrainian roots who gave up a well-paying corporate job in Buenos Aires.

Her grandfather was a Ukrainian nationalist who fought in World War II against the Soviets and chose to surrender to British forces in 1945.

His brothers-in-arms succumbed to the promises of Soviet officials and were gunned down “half an hour” after laying down their arms, Nazaryk said.

These days, she manages the centre’s international advocacy efforts and is improving her Ukrainian.

“I wanted the job. I got the job,” she told Al Jazeera.

The making of a human rights activist

Matviichuk chose a career in human rights when she met a Soviet-era Ukrainian dissident while in high school.

At that time, artists, rights activists and nationalists who wanted to break free of Russia’s control fought for Ukraine’s independence. Many were arrested, jailed and forcibly committed to psychiatric institutions – but didn’t give up.

“They were very modest, very honest people who say what they think and do what they say,” Matviichuk said.

She graduated from a prestigious law school in Kyiv, studied human rights and earned a doctorate. Later, she worked in a bank to supplement the centre she founded in 2007.

It began documenting rights abuses in Ukraine, neighbouring Belarus and Russia, including protests against Putin’s return to the presidency in 2012 that ended with hundreds of convictions.

It was also in 2007 that Matviichuk received the first of her prizes, an award named after one of her teenage idols, Vasyl Stus, a Ukrainian poet and dissident who died in jail in 1985.

Matviichuk quit her bank job to dedicate herself to the centre full time after Viktor Yanukovych, a pro-Kremlin figure from eastern Ukraine’s Donbas region, was elected president in 2010.

An ex-convict and populist, Yanukovych tried to steer Ukraine away from its pro-West course.

Rallies against his policies called the Euromaidan protests began in November 2013 on Kyiv’s Independence Square.

As Matviichuk was holding training for rights activists from all over Ukraine nearby, police were beating up protesters.

She and her trainees decided to form the SOS–Euromaidan group, which helped the protesters who were arrested, beaten, tear-gassed, detained and tortured by pro-Yanukovych police and supporters.

The group’s members faced threats. Some received ominous invitations to prosecutor’s offices. Others were greeted by armed hoodlums near their homes.

‘Never been so scared in my entire life’

In late February 2014, calls flooded the group’s hotline as protesters clashed with police. Dozens were shot by snipers who activists and Ukraine’s subsequent interim government said were deployed by Yanukovych’s administration.

During the chaos, Matviichuk’s husband, Oleksandr, called her to say goodbye as he was in the centre of the violence.

Matviichuk said she had never been so scared in her life.

Thankfully, he was not hurt.

Yanukovych fled to Russia, and withing days, she sent the first group of observers to Crimea as Moscow was readying to annex the peninsula.

The West responded to the annexation with diatribes and sanctions – but kept buying Russian fuel.

Matviichuk still blames the West for the inaction that made the Kremlin believe that “they can do whatever they want,” she said.

Crimea’s annexation and Moscow’s backing of pro-Russian separatists in the Donbas triggered a new flood of rights violations, including the arrest of Crimean filmmaker Oleh Sentsov.

A Russian court sentenced him in 2015 to 20 years in jail for “terrorism”. Matviichuk campaigned for his release until he was freed in 2019.