They beat prisoners relentlessly and tortured them with electric shocks, waterboarding and mock executions. Three people died in their custody. Yet such was their sense of impunity, the Russians who seized control of a detention center in southern Ukraine last year and filled it with 200 detainees were careless about concealing their identities.
Last week, Ukrainian prosecutors announced war crimes charges against four members of the Russian National Guard — the commander who ran the detention facility and three of his subordinates. They were accused in absentia for cruel treatment of civilians and violating the laws of war.
The case is one of the first to emerge from months of investigations by Ukrainian prosecutors in the southern region of Kherson, which Russian forces occupied for more than eight months until they were forced out by a Ukrainian counteroffensive in November. Investigators say they have uncovered hundreds of crimes that were carried out under the Russian occupation, including executions and deaths in custody, torture, sexual violence and beatings in the recaptured areas.
Investigators in the Kherson region have found 11 detention facilities with torture chambers where men and women were abused. The four men charged with war crimes oversaw the pretrial detention center at No. 3, Thermal Energy Street, in the center of the region’s main city, Kherson. Some of the victims helped identify them from photographs of the Russian National Guard unit that took over the detention center last summer.
Two men and one woman died at the center, investigators said. The men had been beaten and all three had been denied health care, the investigators said, adding that 17 detainees said they had been subjected to sexual torture with electric shocks to the genitals.
The four Russians accused are Col. Aleksandr Naumenko from the southern Russian city of Rostov-on-Don, Aleksandr Bocharov from the Krasnodar region, Anver Muksimov from Stavropol and Aleksandr Chilengirov from the Orenburg region.
The National Guard was established in 2016 by President Vladimir V. Putin to consolidate Russia’s various Interior Ministry units. The National Guard, which is separate from the Armed Forces, is responsible for internal security and answers directly to the president.
Investigators said they had identified the National Guard unit using information from Ukraine’s intelligence service, telephone intercepts and witnesses. Much of the violence was gratuitous and applied during interrogations to force confessions, Andriy Kostin, the prosecutor general of Ukraine, wrote in a Facebook post about the Kherson case.
“Confessions were ‘beaten out’ of people about things they did not do,” he wrote, comparing the methods to those of the secret police during Joseph Stalin’s purges.
Oleksii Sivak, 38, a Ukrainian seaman who became an activist during the occupation, painting Ukrainian flags, national symbols and graffiti around Kherson city, was arrested in August; he suffered beatings and electric shocks, including to the genitals, during interrogations. He was able to identify at least one of the men accused.
“Every question was followed by an electric shock or a punch,” he said in an interview in Kyiv. “If you fell from the electric shock onto the floor, they kicked you and put you back on the chair.”
The shocks continued for about an hour, with only 30-second breaks, he said. “The moment you enter, they start doing it and they take it in turns on this dynamo machine,” he said. “There was a man asking questions and men who were torturing.”
At one point, he caught sight of his interrogators when they pulled off a knitted cap covering his eyes and put a pistol to his head to force a confession.
“I saw, at that moment, two guards and two intelligence servicemen who took me from my home,” he recalled. The men were all wearing balaclavas, he said, as was the colonel in charge of the detention center.
But the guard who escorted him to the torture chamber did not bother to wear a mask, Mr. Sivak said, and he was able to identify the guard from photographs.
Mr. Sivak’s neighbor, Roman Shapovalenko, 38, who was arrested on the same day, said in an interview that he had suffered electric shocks and beatings that broke his ribs. On one occasion, his torturers stabbed him in the leg and jumped on his chest, he said, and he lost consciousness several times while being waterboarded. Another time, his torturers pulled off the hat concealing his eyes and made him attach the wires to his genitals himself. He saw at least three people in the room, but they all wore balaclavas.
Mr. Shapovalenko said the most painful torture had involved electric shocks to the earlobes. “You have flashes like lightning in your eyes,” he said. “I could not sleep for three days.” He joked with his cellmates that he had obtained a Wi-Fi connection and that he was watching YouTube videos and war movies play before his eyes.
One of Mr. Shapovalenko’s cellmates, a man in his 50s named Ihor, died from the vicious beatings he had received, he said. Ihor was interrogated for three or four days, and after they returned him to the cell, the Russian guards ordered him to write a statement and kept rousing him to prevent him from sleeping. On the fourth day they let him sleep, but by then it was too late and he died that night.
“They never read his testimony,” Mr. Shapovalenko said. “All of us thought we would end up like that.”
Another man, Serhii Ruban, 42, a sales consultant, also died in the detention center, prosecutors have established. His mother, Nina Ruban, 70, said she last saw him alive when he was arrested on June 12. Six days later, she was told at the army headquarters that her only son was dead.
Two witnesses saw him being heavily beaten in the corridor and inside their cell, prosecutors said, and a third witness moved his body to the morgue. Investigators found his body among the remains in a mass grave, and in February, his mother identified him by a tattoo on his knuckles. He had multiple rib fractures, leaving her in no doubt that he was beaten to death.
“He was all broken,” she said, weeping.
Oleksandr Chubko and Dyma Shapoval contributed reporting.