Stephen Hubbard, a U.S. citizen, arrived at Lackland Air Force Base in San Antonio early Thursday morning, marking the end of a four-year period of detention in Russia. Hubbard had been living in Ukraine at the time of his initial arrest.

Russian authorities had leveled specific accusations against Hubbard, claiming that he served as a mercenary fighting on behalf of Ukraine following the Russian invasion. While the return of American detainees is often the result of high-level diplomatic negotiations, details regarding the specific terms or agreements that led to Hubbard’s release remain limited. The arrival at the Texas military base follows a trend of prisoner exchanges and releases involving U.S. citizens held by the Russian government throughout the duration of the war in Ukraine. Hubbard’s case has been noted for his long-term residency in the region prior to the escalation of hostilities.