Here's what the original news story said:
http://abcnews.go.com/Blotter/aurora-dark-knight-shooting-suspect-identified-james-holmes/story?id=16818889
Admittedly, the story was written to make it sound as if the mother immediately knew her son might do something like this. But I think the writer of the story (who may be a different person from the reporter who contacted her) may be misinterpreting the conversation. I imagine that the reporter did a phone directory search for people named Holmes in the San Diego area to try to find his parents. When he contacted her, he probably said, "Are you the mother of a James Holmes of Aurora?" And she probably said, "Yes, you have the right person." Then, when the reporter proceeded to tell her what her son had allegedly done, she probably said, "I need to call the police...I need to fly out to Colorado." Despite the way the story is worded, I'm not convinced that the mother had any knowledge that her son might do this.
JMO.