Who Killed?

Who killed Attila's son? She asked for the boy to be brought to the dinner. She also had a knife sitting in front of her. Yet, Hagen was blamed.

I'm not familiar with anything except this movie. While it seems Hagen didn't protest that he actually did kill the boy, I'm not sure why. It makes perfect sense she killed her son to turn Attila against his guests.

NEVERMIND I read the synopsis of Wagner's Ring and it was Hagen. Case closed. I guess if she did it, it would have to have been now, it's too modern a plot twist.