U.S. Marine veteran Robert Gilman was released Tuesday from Russian custody after spending 1,666 days imprisoned, a development the State Department characterized as part of an exchange with Russia that involved no other concessions.

Gilman, a U.S. citizen, was arrested on January 17, 2022, in Voronezh, Russia, and ultimately sentenced to 10 years. According to a representative for the Gilman family, Kieran Ramsey, Gilman endured harsh and abusive treatment while in custody that left him in a catatonic state.

Ramsey detailed that Gilman's initial travel was not intended to include Russia. In November 2021, while en route to Moldova, he became severely ill and had to stop in Moscow. He stayed with a relative to recover. In January 2022, shortly after what he believed was a full recovery, Gilman went to the U.S. embassy to renew his passport. During this time, he reportedly became violently ill again. Russian police approached him, mistaking his condition for intoxication, and claimed he assaulted them. He was subsequently arrested and charged, an event that escalated into a lengthy detention.

Gilman was transferred from prison to a civilian hospital in Voronezh on June 30. His family has expressed grave concerns about his medical condition, stating he was in a catatonic state and being fed through a nasal tube.

Gilman's sister, Lexie Hudson, expressed gratitude to former President Donald Trump and Senator Ed Markey for their roles in securing his release. "I am so grateful to President Trump for saving my brother’s life. There is no other reason that Robert is alive today other than that President Trump heard about the case and took action," Hudson said in a statement.

Ramsey, who has experience in hostage recovery, described Gilman's case as one of the most severe he has encountered regarding the treatment of Americans in Russian prisons, noting Gilman's critical condition and risk of death. "The fact that he is in a near catatonic state. And again, we believe he's at risk of death is just frightening for this family. It should be frightening to every American that sees this report," Ramsey told Fox News.

Gilman is the third U.S. Marine to be detained in Russia in recent years, following Trevor Reed and Paul Whelan, both of whom were later released in prisoner swaps. Global Relief, a nonprofit organization, noted that five other Americans remain wrongfully detained in Russia, some with deteriorating medical conditions, and urged the administration to secure their release.

Ramsey stated that Gilman will undergo a full medical assessment upon his return to the U.S. and will be joined by his family at a U.S. military hospital in Texas to begin his recovery.