BUCHA, Ukraine—For police detective Ivan Dulkay, retribution for the butchering of his compatriots here, Russia’s worst war atrocity, comes not in the furnace of the battlefield, but through cold investigation and deduction.

He wants to find out—and to prove: Who exactly killed more than 300 people in this Kyiv suburb right at the start of Russia’s invasion in 2022? And who ordered the killing spree?

Russia has killed tens of thousands of civilians during nearly five years of war, increasingly by long-range strikes, as the front line is largely stuck. What makes Bucha stand out is that most of the killings were carried out at close range with bullets. When the Russians retreated from this leafy Kyiv suburb after one month of occupation, corpses lay in the streets and in mass graves.

The International Criminal Court has issued arrest warrants for six senior Russian officials, including President Vladimir Putin, for war crimes including forced deportation of children and targeting of civilian facilities with missiles.

Dulkay is working on a different plane. He is hunting the Russian triggermen and their immediate commanders, aiming to work his way up the chain of command.

The 31-year-old is still relentlessly pursuing leads after four-and-a-half years. He and his team have created an interactive map showing where each of the victims was killed, interviewed hundreds of witnesses and exhumed bodies in the search for bullets to tie killers to victims.

On the wall of his modest office are photos of dozens of Russian suspects as well as the Ukrainian victims. In the corridor outside stands a wooden model of Yablunska Street, a notorious kill zone. More than a dozen plastic figurines lie prone or face up, with one on its side under a bicycle.

“When I am sleeping, I wake up and see images. It’s hard to get away from them,” Dulkay said in an interview. “But murders aren’t solved at night. The main thing is not to hurry, but to concentrate.”Russia denies any murders took place in Bucha, asserting that the massacre was faked by Ukraine. Dulkay aims for a forensic dismissal of Russia’s claims—and a measure of justice.

It was shortly after Russia’s retreat from Bucha that Ukraine’s government handed the case to Dulkay, a detective whose standard fare before the war was robbery, murder and organized crime.

Dulkay had known Bucha as an affluent Kyiv suburb with parks and woodland where he would travel with his family. Now, he and his team of 12 detectives set out to gather as much evidence as possible from hundreds of murder scenes. They have conducted hundreds of interviews, listened to hours of intercepted Russian communications and watched footage from CCTV cameras and Ukrainian drones.

It can be grueling work. Dulkay said he tries to take a clinical approach to examining horrific scenes including dead children or charred remains.

“I don’t have emotions working with bodies,” he said in a soft and measured voice. “A normal person sees a car shot up with a body. For me, I look and start looking at questions: What’s the mechanism? How did they shoot? Why did they shoot?”Still, he tries to leave his work at the office. He won’t look at pictures or read case materials when he is at home with his 1-year-old daughter.

The work is paying off. Dulkay said his team has solved 86 of the killings and charged 32 Russian soldiers with murder and torturing civilians.

His methodical approach drove forward the investigation into the killing of Volodymyr Kovtun, a 45-year-old who enjoyed soccer and had been hiding in a basement. He was shot when he returned to his apartment to collect his belongings and retrieve his dog.

In summer 2025, Dulkay led a team exhuming the body in search of the killer’s bullet. He directed the process to try to prevent damage to the remains and donned a white forensic suit to approach the body. No bullet was found, but forensic experts established that the wound to the skull had been caused by a 9mm round, typical of the Vintorez, a Russian sniper rifle.

The three bullets found in Kovtun’s apartment were of the same caliber. Police traced them to the rifle of a Russian sniper, Sgt. Artyom Dementiev, who they say used the nine-story apartment building where Kovtun lived as an observation point.

In late June, detectives carried out an investigative experiment. They dragged a sand-filled dummy into the apartment and placed it in the entrance hall. A forensics expert fixed a sticker over the dummy’s left eye and another on the nape of its neck to show how a bullet pierced the victim’s head. A ballistics specialist concluded that the distance between the shooter and the victim was about 5 feet, based on the caliber of the bullet found at the crime scene and photos of the body, which show blood covering the opposite wall all the way up to the ceiling.

The experiment allowed police to conclude that Kovtun met his killer at the front door and was shot dead through the eye.

On March 10, the day of Kovtun’s murder, police say Dementiev also kidnapped and interrogated one man he encountered in the stairwell, striking him about 40 times on the head and leg with a kitchen mallet, the man later told police. “His crimes had clearly sadistic features,” said Dulkay.

Dementiev, Dulkay said, was a prolific killer with at least six murders to his name. (He died on the battlefield last August, Dulkay said, his voice tinged with disappointment that he won’t face court.) Above the triggermen are those who ordered the killings.

Dulkay traced Dementiev to a reconnaissance platoon of 12 Russian soldiers who were deployed on Yablunska Street.

Residents on the street recalled the commander was a man named Tareyev with the call sign Uspekh, meaning Success. Security camera footage showed him carrying a commander’s radio. At a nearby residential complex, investigators found a radio with a list of call signs of junior commanders in airborne companies, including the head of a reconnaissance platoon: Uspekh.

Dulkay had his man: Lt. Artyom Tareyev. But he needed to prove his involvement. The nature of the killings gave a clue.

One of the platoon’s victims, a retiree called Kostyantyn Shevchenko, identified Dementiev as the man who shot him in the leg when he went out to charge his phone at a public electricity generator.

Iryna Filkina was shot from her bicycle on the street. Her bright red manicure on her stiff dead hand became a symbol of Russian brutality in Bucha.

Valeriy Kizilov was shot dead after leaving his basement to check on a noise in his backyard. Kizilov’s wife, Lyudmyla, recognized Tareyev and his men as they later occupied her house. Testimonies from witnesses demonstrated that soldiers had orders to shoot at anyone in their zone.

“They said they had received an order to shoot at anyone who was wearing black, who had tattoos, and who was moving,” said Raisa Golenok, a retired actress who lives on Yablunska Street.

Two Russian prisoners of war who were in Bucha confirmed this account. Dulkay also consulted with military experts who said that the way the platoon acted was in line with Russian doctrine and wouldn’t have opened fire without permission from superiors.

On July 1, Ukraine’s Prosecutor General’s office charged Tareyev with war crimes and murder in a case in which he faces a life sentence. Police said they have evidence that Tareyev and his unit are responsible for at least 22 murders on Yablunska Street and around it.

Dulkay said that Tareyev serves as a military instructor in Siberia. Relatives of victims worry he will never face justice.

Walking down Yablunska Street, Dulkay said thoughts of the victims drive him to pursue the killers and keep faith in eventual justice.

“They were ordinary people who had their own life goals, families and concerns. I know the reasons why these people ended up on this street, what motivated them. But they did not know what awaited them here,” he said. “No matter how many years it takes, accountability must come.”