"I haven't got a callback from the state department yet… [Sheriff's Office is waiting the callback] to verify that they were adopted from Kazakhstan," Spurling told RIA Novosti on Saturday.
He added that he can not rule out that the teenagers were adopted from Russia, because he had information about their adoption from Kazakhstan, but it had not been verified yet.
Earlier on Saturday, Spurling said earlier that the killed children may have stemmed from Kazakhstan, while the county's Coroner Jane Pentz told Sputnik that, according to police, the boys were of Russian nationality.
Later in the day, Dan Reeber, US State Department representative responsible for diplomatic security matters in Seattle told Sputnik that the State Department can not confirm the citizenship of the two killed boys.