Who are the six U.S. citizens who remain in detention in Russia following the Ksenia Karelina exchange?

Last Thursday, U.S.-Russian citizen Ksenia Karelina returned to the United States after being released in a prisoner exchange between Moscow and Washington, thanks to the efforts of President Donald Trump's administration. 

Karelina spent more than a year in a Russian prison, charged with "treason" for donating to a pro-Ukrainian charity. This exchange, the second since Donald Trump took office, marked a new chapter in the strained relations between the two countries.

However, there are still at least six U.S. citizens in detention. The citizens continue to serve sentences in Russian prisons, facing charges ranging from "espionage" to "assaults" and "drug trafficking," as reported by Infobae.

Stephen Hubbard: Convicted of "mercenarism"

Stephen Hubbard, a man in his 70s originally from Michigan, is serving a nearly seven-year sentence after being convicted by a Russian court of fighting as a mercenary in the Ukrainian army. Hubbard, a retired English teacher, was residing in Izyum, northeastern Ukraine, when Russia launched its offensive in February 2022.

Captured shortly thereafter, he was held incommunicado for two and a half years before being tried in Moscow in October 2024 on charges of receiving payments to join a Ukrainian territorial defense battalion. A Ukrainian soldier who shared captivity with him told the AFP that Hubbard was subjected to beatings with sticks and batons, forced to simulate sexual acts and deprived of food.

Gordon Black: Soldier sentenced for "robbery" and "threats"

Gordon Black, a 34-year-old American soldier, was sentenced in June 2024 to three years and nine months in prison by a court in Vladivostok, in the Russian Far East. He is charged with threatening to kill his girlfriend and robbing her. Black, who had served in Afghanistan and Iraq, was visiting a Russian woman he met while stationed in South Korea. Although a court reduced his sentence Monday to three years and two months, U.S. media have speculated that his arrest may have been a "honey trap."

Robert Gilman: Ex-Marine accused of "assaults"

Robert Gilman, a former Massachusetts Marine, is serving a seven-year sentence for assaulting Russian police and prison guards. Initially convicted in 2022 of assaulting an officer while drunk, his sentence was extended after he was charged with beating prison staff and a criminal investigator. His defenders maintain that the charges are baseless and allege that he has been subjected to "forced drugging" and "torture" in prison.

Michael Travis Leake: Musician sentenced for "drug trafficking"

Michael Travis Leake, a former U.S. paratrooper and leader of the Moscow-based rock band Lovi Noch, was arrested in June 2023 and sentenced to 13 years in prison for selling illegal narcotics. According to CNN, Leake had been living in Russia for years prior to his arrest. His case has been notable for the severity of the sentence and the circumstances of his arrest.

Joseph Tater: Faces charges of "assault"

Joseph Tater faces a possible five-year sentence for allegedly assaulting a police officer following an altercation with hotel staff in Moscow. At a court hearing last year, Tater rejected his U.S. citizenship and claimed to have been persecuted by the CIA for years. Last week, Russian state media reported that he was forcibly committed to a psychiatric hospital after being diagnosed with "impulsivity" and "delusional ideas" by a group of Russian doctors.

Gene Spector: "Espionage" without details

Gene Spector, born in Russia and a naturalized American citizen, received a 15-year sentence in December 2024 on "espionage" charges. To date, no specific details about the charges against him have been released, creating uncertainty about his case.

The plight of Hubbard, Black, Gilman, Leake, Tater and Spector underscores the challenges still facing the Trump administration for those who remain behind bars in a Russian judicial system frequently questioned for its lack of impartiality.