Ukrainian special operations forces reportedly went behind enemy lines to arrest a former commander of pro-Russian separatists who is suspected of being involved in the shootdown of Malaysia Airlines Flight 17.

Ukrainian forces captured Vladimir Tsemach June 27 at his apartment in Snizhne, a city in the self-proclaimed Donetsk People’s Republic in eastern Ukraine. Tsemach, 58, is believed to have been the commander of a Russian-backed air defense unit when MH17 was shot down on July 17, 2014. The crash left 283 passengers and 15 crew members dead. A majority of the passengers on the flight, which left Amsterdam for Kuala Lumpur, were Dutch.