A key suspect in the downing of MH17 six years ago has been arrested on unrelated charges in Ukraine, according to BBC Russia. Leonid Kharchenko is the only Ukrainian suspect and, when the passenger plane was shot down in July 2014, he was commander of a combat unit for the self-proclaimed Donetsk People’s Republic. He is one of four defendants formally charged with involvement in the crash in the case that is underway in the Netherlands. The BBC’s Russian service reported that Kharchenko was arrested in March in Donetsk—but not for reasons related to the crash. He was reportedly arrested for allegedly taking part in an illegal search in 2014 and for illegal possession of weapons. All 283 passengers and 15 crew were killed when the plane was downed by a Buk surface-to-air missile launched from separatist-controlled territory in Ukraine.