Question About Doctor Who?

O.K, so we finally know that River Song is Amy & Rory's daughter......but what i want to know is, who did she kill to be put in the storm-cage prison?...........she says she in for killing a good man......now given the poem in the last episode is "Demons run, when a good man goes to war", it's safe to ume the good man is the doctor..........however, the doctor was killed by the astronaut in the america episode.....now even if the little time-lord-ish girl is river, she broke free of the suite, so unless she was somehow put back into it, she couldn't have killed the doctor..........speculations welcome