Stephen Hubbard, 72, was detained in eastern Ukraine in April 2022 and accused of fighting for Ukraine.
Why are people contesting the evidence against the former UK nurse, convicted of killing seven newborns?
US execution comes days after that of Marcellus Williams in Missouri, where victim’s family also asked for clemency.
Judge acknowledges Iwao Hakamada was wrongfully convicted for murders at miso factory in 1966.