Toktogul Kakchekeyev, a spokesman for the Prosecutor-General's Office in Bishkek, says that although the case is considered murder, the U.S. soldier cannot be charged because of the immunity granted to U.S. service personnel at the Manas Air Base.
The shooting took place in December when truck driver Aleksandr Ivanov was going through a security check at the entrance to the base.
The U.S. military says Ivanov was fired upon after he threatened the U.S. soldier with a knife.
Earlier this week, a lawyer for the Ivanov family said the U.S. military had offered about $1,100 in compensation -- a sum the family called "humiliating."
(with material from AP)