A spy inside Russia’s army. The Wall Street Journal tells the story of the lieutenant who helped Ukraine kill hundreds of his fellow soldiers.

Lev Stupnikov came to public attention in September 2025. In an interview that month with Ukrainian YouTuber Dmytro Karpenko, he revealed that he was a Russian officer sent to fight in Ukraine who had spent more than six months supplying Ukrainian forces with targeting information to help them strike his fellow soldiers. RT said more than 200 Russian soldiers had died because of him. Chechen special forces announced a manhunt for Stupnikov, who by then had crossed the front line and was fighting with the Russian Volunteer Corps. The Wall Street Journal recounted the story of Stupnikov, his family, and his decision to help Ukraine target Russian troops. Meduza summarizes the report.

Lev Stupnikov is 26. He was born in Kazakhstan. His father left the family when he was very young. His mother, Tatiana Yantsen, raised him and his younger sister, Alisa, alone. When Lev was a teenager, Tatiana moved to Russia through a government resettlement program for people with ties to Russia and settled in Omsk. Stupnikov attended a cadet school there, then moved to St. Petersburg to study at the Military Academy of Communications from 2018 to 2023.

In 2021, Lev married his girlfriend, Liza, and was considering giving up his military career. But Russia’s full-scale invasion of Ukraine changed everything. Stupnikov was shocked by the invasion. In the summer of 2023, he graduated from the academy as a lieutenant and was assigned to the 36th Guards Motorized Rifle Brigade, based in Russia’s Zabaykalsky region. His deployment to Ukraine was only a matter of time — it came in November 2023.

By then, Tatiana Yantsen had long since become disillusioned with the Russian authorities. The war shocked her as much as it did Lev. She took Alisa out of school to protect her from pro-war propaganda and contacted human rights advocates to try to get her son out of the army. Most advised arranging an escape through Belarus and Armenia. Tatiana knew Lev would have to change planes in Moscow on his way to the front. She urged him to board a flight to Kazakhstan and hide with relatives. He rejected the plan: It was too dangerous.

In February 2024, three months after her son was sent to the front line, Tatiana contacted Dmytro Karpenko. A Ukrainian programmer and blogger, he posted interviews with Russian prisoners of war and defectors on YouTube and offered payments to people willing to help the Ukrainian military. Tatiana wanted to know whether he could help her son desert. When Lev learned that his mother had been corresponding with Karpenko, he began watching the blogger’s videos, then contacted him on WhatsApp. He said he was ready to cooperate and surrender. Lev declined payment.

Stupnikov later told Karpenko in an interview that, while still serving in the Zabaykalsky region, he had decided he would find a way to surrender if sent to the front.

After that first WhatsApp message, Karpenko and Stupnikov spoke by phone and agreed to work together. They devised a code: Each greeting had to be followed by a prearranged number, the day of the month plus five. A message sent on February 20, for example, had to begin with “Hello 25.” Without it, Karpenko would know his source had been compromised.

The very first strike Stupnikov helped direct killed scores of his fellow soldiers. He sent his handler the coordinates of a training ground near Volnovakha where Russian soldiers were lined up. A HIMARS rocket strike killed 68 people and wounded another 60. Among the dead was Colonel Gusein Musayev, commander of the 36th Motorized Rifle Brigade. Stupnikov survived by pretending he urgently needed to use the bathroom.

It was the most successful operation Karpenko and his “moles” had organized to date. Over the following months, Stupnikov shared radio frequencies, troop locations, and battle plans with his handler. His 36th Brigade was rapidly losing personnel. Eventually, of all the officers he had started out with in his battalion, he was the only one left. The others had been killed, wounded, or transferred to other parts of the front.

Stupnikov was deeply anxious. At night, he dreamed of the explosions he had helped cause. Trying to shake off his guilt, he told himself that those killed had been bad people. The more successful he was, the more he feared being exposed. “It was constant, endless tension. Real spies get training in espionage. I had received no such training at all,” he said.

In July 2024, Stupnikov crossed the front line. Under surveillance by a Ukrainian drone, he reached a Ukrainian reconnaissance team and gave the password: “Peanut shop.” He was blindfolded and taken to Ukrainian positions. Soon afterward, Denis Kapustin, commander of the Russian Volunteer Corps, visited him and offered him a place in the unit. Stupnikov wanted to start a new life somewhere else, but he understood that Ukraine was safer than other countries for defectors like him. He agreed to join.

With Ukrainian help, Stupnikov got his mother and sister out of Russia. His wife refused to leave. When he gave his interview to Karpenko a year later, she spoke to RT. “He asked me to move abroad with him. He didn’t say it was Ukraine. He just said I should come join him. I made it clear right away that I wasn’t going anywhere. I’d never been interested in moving abroad anyway. He started freaking out, saying I was betraying him, saying I was a bad wife if I wouldn’t follow my husband. I told him then that I might be a bad wife, but I would never, ever abandon my parents or my country,” Liza said.

RT also spoke to several people it identified as relatives of soldiers killed in strikes directed by Stupnikov. Among them was Tatiana Guryeva, whose son Pavel was killed in the February 2024 strike on the training ground near Volnovakha. Guryeva said Pavel and Lev had been friends. “My son told me about him more than once. He thought Lev was a kind, good-hearted person. He fit right in with the unit. And Pasha liked his name so much that he even started calling himself Lev on social media and dreamed of giving his son the same name… Now that I know who directed the missiles at that training ground, I’m just so shocked…” she said.

Citing Russian military personnel, RT reported that Russian military losses from strikes directed by Stupnikov exceeded 200. The Wall Street Journal put the figure at more than 300.