The moment he laid eyes on Shinzo Abe's ashen face, Shingo Nakaoka knew that any attempt to revive the former Japanese prime minister was likely to be in vain.

By the time the 64-year-old doctor had rushed to the scene from his nearby clinic within minutes of Abe's shooting on July 8, the stricken lawmaker's face was bloodless from deep gunshot wounds to the neck.

"What struck me immediately was just how pallid his face was," Nakaoka said by phone days after the assassination.