But Daniel didn't have intentions to be a cold-blooded murderer. He thought he was doing the world a good for the better, because Alexander informed them that they were murderers themselves. Though in contrast, the little girl and her mother were in fact innocent. The flashback in the withered nave says so, since he went to the farm to kill the Zimmerman family, and they did no crimes whatsoever.
I still only blame Daniel for half the murders he actually did, since he did it without realizing. Though I'd hate to be in Daniel's position, he's still part of the blame.