The messages, reports from across Ukraine, scroll in real time:

One civilian dead.

Thirteen military casualties.

Five civilians injured.

Prosecutor General Iryna Venediktova glances at her cell phone. The stark numbers and bare-bones accounts that unreel in her hand are just the start; her staff will catalog them, investigate them -- and try to bring the Russian perpetrators of war crimes to justice.

This is her purpose: To make Vladimir Putin and his forces pay for what they have done. While courts around the world are working to hold Russia accountable, the bulk of the investigation - and the largest number of prosecutions - will likely be done by Ukraine itself.

For Venediktova, this is personal.

"I protect the public interest of Ukrainian citizens. And now I see that I can't protect these dead kids," she says. "And for me it's pain."

This story is part of an ongoing investigation from The Associated Press and FRONTLINE that includes the War Crimes Watch Ukraine interactive experience and an upcoming documentary.

The first woman to serve as Ukraine's prosecutor general, Venediktova speaks with steely resolve and occasional humor, and approaches her task with a relentless work ethic.

Venediktova, a 43-year-old former law professor, is on the move every few days, the jackets and dresses of her old life increasingly replaced by olive fatigues and a bulletproof vest. She takes meals hurriedly in the car or skips them entirely.

There are no office hours anymore. There are only war hours, which start early and end late, as Associated Press reporters who spent a day with her would learn.

Her office has already opened over 8,000 criminal investigations related to the war and identified over 500 suspects, including Russian ministers, military commanders and propagandists -- even as an array of international war crimes investigations pick up steam.

"The main functions of the law are to protect and to compensate. I hope that we can do it, because now it's just beautiful words, no more rule of law," Venediktova says. "It's very beautiful words. I want them to work."

On a Tuesday morning, Venediktova marches up to a thick line of refugees waiting in the chill sun to register at a district administration building in Lviv. Her security detail, armed and dressed in black, hovers as she stepped into the crowd of women and children.

Venediktova has stationed prosecutors at refugee centers across the country and at border crossings, trying to collect the shards of suffering of millions of Ukrainians and transform them into fact and evidence before they vanish.

Venediktova sweeps upstairs, down a narrow hallway to a bare room with two large black desks that she calls "the heart of the war crimes office" in Lviv. Her war crimes unit has around 50 dedicated prosecutors, but she's repurposed all her staff to focus on that mission.

Many don't want to show their faces publicly. There are grave questions of security, both for her people and the information they collect. Prosecutors here tend to speak of the future with grim pragmatism. It's not just the unpredictability of war; it's a tacit acknowledgement that they themselves might not be around tomorrow to finish what they've started.

Prosecutors ply the line of refugees at Lviv's center each day, looking for witnesses and victims willing to submit a statement. Some stories are not told. People have come too far, they're too tired. Or scared. Their infants are fussing. They have places to go.

Interviews can take hours. Bent over laptops, prosecutors wait out people's tears to ask what the shelling sounded like, what kind of spray munitions made on impact. They ask what uniforms, what insignia soldiers wore. This is the raw material of accountability, the first link in a chain of responsibility Venediktova hopes to connect all the way to Russia's leadership.

Ala, 34, sits with prosecutors and explains how she'd lost her home. She doesn't want her last name published because her 8-year-old daughter remains trapped in Russian-held territory.

Ala promises to return with a fragment from a mortar that destroyed her apartment in Vorzel, a town a few kilometers west of Bucha. She'd collected the metal, dense and grey in her hands, as a memento of what she'd survived. And as evidence.

"We need proof for them to be punished," she says. "I am lucky. I am still here to talk about what happened to me."

Shortly before noon, Venediktova leaves the refugee center and climbs into a black SUV headed to the Polish border, an hour or so north. A police escort speeds her through a landscape of rough houses and the wintery bones of trees, past old cemeteries, rusted children's swings, the shining domes of churches. The only signs of war are defiant billboards proclaiming victory for Ukraine and death to the enemy, and checkpoints with sandbags and hedgehog barricades to stop tanks that have not yet come.

Venediktova knows these roads well. She rides them endlessly back and forth to meet foreign officials who don't dare venture into a country at war.

"I live in a car actually," she says. "I need help, support, advisers. I need people who understand what will be next."

Her office cooperates closely with prosecutors from the International Criminal Court and nearly a dozen countries, including Poland, Germany, France and Lithuania, all of which have opened criminal investigations into atrocities in Ukraine.

She has taken on high-level legal advisers from the U.K. and is working with the United States and the European Union to build mobile investigative teams with international expertise. Clint Williamson, a former U.S. Ambassador-at-Large for War Crimes Issues, helps oversee that effort, which is funded by the U.S. State Department.

"We have to confront this," Williamson says. "There's a need to show that countries are determined to stand up for international humanitarian law and hold people so flagrantly violating it accountable."

Part of their task now is to make sure that the evidence being collected is up to international standards, so the testimony of people like Liudmila Verstiouk, a 58-year-old woman who survived the siege of Mariupol, won't be thrown out of court.

Venediktova meets Verstiouk in a makeshift office at the Krakivets crossing on the border with Poland. She arrived from Mariupol with her papers, her phone and the clothes on her back - a velour dress, black stockings, white winter boots. Her apartment was bombed on March 8, and she told prosecutors that when she fled, she left her 86-year-old father behind in the burning building. He has Alzheimer's and cannot walk.

Verstiouk says she spent a week sheltering at Mariupol's drama theater. She left the day before bombs killed an estimated 300 people there.

She has not been able to reach anyone who was inside by phone. Or her father.

"Why did Russia attack me?" she says. "It destroyed my city - for what? For what? Who will give me an answer to that, and how do I go on living?"

In the course of a five-hour interview, prosecutor Stanislav Bronevytskyy takes Verstiouk's statement. "She can remember every detail, each minute and second," he says.

He types out Verstiouk's story and uploads it to a central database.

Vast swaths of Ukraine have been transformed into potential crime scenes. Each day, the tragedies multiply, creating an insurmountable pile of facts that must be established and saved.

There is far too much work even for the more than 8,000 staffers who work for Venediktova. Back from the border by mid-afternoon, Venediktova continues her campaign for support, on Zoom calls with Amal Clooney and a group of international donors.

When President Volodymyr Zelenskyy appointed Venediktova, in March 2020, she inherited an office plagued by allegations of corruption and inefficiency and a legal code outside experts have said is badly in need of reform.

She has pitched herself as a reformer. Thousands of prosecutors have been fired for failing to meet standards of integrity and professionalism, and so she's got an office that is not fully staffed preparing war crimes cases against what she predicts will be 1,000 defendants.

Venediktova has been building alliances with human rights groups - some of which have a history of antagonism with Ukrainian authorities -- and an often-distrustful public.

In March, a group of 16 Ukrainian civil society groups formed the 5AM Coalition to document potential war crimes. In addition to analyzing open-source material, they manage networks of trained monitors who gather evidence across the country to share with prosecutors.

They're joined by researchers around the world, at places like the Centre for Information Resilience, Bellingcat and the International Partnership for Human Rights, who have been scouring the flood of social media postings to verify what happened and who is responsible.

Venediktova also has encouraged ordinary citizens to help by collecting information with their smartphones and submitting it online to warcrimes.gov.ua. Five weeks into the war there were over 6,000 submissions.

Artem Donets, a criminal lawyer who joined the territorial defense forces in Kharkiv, says he is part of a Telegram group of 78 lawyers who are all pitching in on evidence-gathering, picking up incidents that prosecutors and police may not have time to get to.

"We are a law battalion," he says.

On the day he spoke with the AP, Donets had gone out to document the latest attack on civilian infrastructure in Kharkiv. He found himself in front of his own home.

As usual, he pulled out his mobile phone. He took GPS coordinates and trained his camera on a crater in the asphalt, tracing its shape with his finger. "Damage to the facade of the building," he said in a flat, professional voice. "Destruction of glass, windows, doors."

Donets reported finding a rocket from a cluster munition sticking out of the ground 100 meters (328 feet) away. Cluster munitions split open and drop bomblets over a wide area and have been banned by over 100 countries. Using such indiscriminate weapons in what was a residential area with no Ukrainian military presence could count as a war crime.

He sends his incident report to the International Criminal Court and uploads it to Venediktova's database.

"It was quite a strike for me," Donets says. "I hope when this war ends to build a better house for me and my family. I hope. We have no options. Either we win this war, or we will be occupied and swept from history."

The horrors Venediktova and her networks of allies are documenting - mass graves, apparent assassinations of civilians, indiscriminate shelling, repeated attacks on hospitals, forced disappearances, torture, sexual violence, cities under siege, denied food, water and humanitarian aid - are not new.

Putin's military and his proxies have used similar tactics in Chechnya, Georgia, Syria, Crimea and the Donbas region of eastern Ukraine. Despite years of copious documentation, Western powers never really pushed back.

That changed at 5 a.m. on Feb. 24, when Russia started dropping bombs on its neighbor. Those years of unanswered atrocities now weigh on Venediktova.

"I was a university professor, and for me rule of law wasn't just a song. When I spoke with my students about rule of law, about human rights, I actually trust in this. And now I feel that what I trust, it does not work," Venediktova says. "Maybe we should take the best minds in the legal system, in jurisprudence of the world and create something new."

In the meantime, she has a more concrete objective: money.

As evening falls, she sits with her deputies in a darkening room and asks for another espresso. The jarring notes of an inexperienced clarinetist waft in from a music school next door.

Venediktova's team reports on progress in their ongoing search for the overseas assets of war crimes suspects. One of her priorities is to seize the money of war criminals and give it to victims. She will need cooperation from countries around the world where Russian suspects have stashed their wealth. Many countries can't legally seize assets for a foreign court.

Ukraine is also crowdsourcing this global treasure hunt, with a portal in English, Russian and Ukrainian, where anyone can upload tips about assets .

There is, of course, an even bigger prize that lies just out of reach: Hundreds of billions of dollars of Russian assets frozen by the U.S., E.U., U.K., Switzerland and others. Maybe one day that too could be used to fund reconstruction and reparations in Ukraine.

Shortly before 9 p.m., Venediktova appears on national television, as she does most evenings. She reassures her people that guilt will be punished and suffering compensated.

"My first joy will be victory when we sell someone's villa, yacht, and our ordinary Ukrainians, who were forced to flee their homes, will physically receive this compensation," she says. "Thank you, good evening, see you soon."

From The Associated Press