(a) A person owing allegiance to the state commits the offense of treason when he knowingly levies war against the state, adheres to her enemies, or gives them aid and comfort. No person shall be convicted of the offense of treason except on the testimony of two witnesses to the same overt act or on confession in open court. When the overt act of treason is committed outside this state, the person charged therewith may be tried in any county in this state.

(b) A person convicted of the offense of treason shall be punished by death or by imprisonment for life or for not less than 15 years.