At a press conference today, Bolat Abilov -- who chaired the Naghyz Ak Zhol (True Bright Path) party along with Sarsenbaev and was, with him, a leader of the For a Just Kazakhstan bloc -- said Sarsenbaev's death was a "political murder."
Official details of the shootings are unclear. However, Abilov says the bodies were found with hands tied behind their backs and with shotgun wounds to the back and to the head.
Sarsenbaev previously served as Kazakhstan's ambassador to Russia. He also served twice as the head of Kazakhstan's Information Ministry.
The U.S. State Department called today for "an immediate and thorough investigation into the circumstances of [Sarsenbaev's] death."
President Nursultan Nazarbaev has ordered an investigation.