Mother kills son over Ice Cream?

Mother kills son over Ice Cream? 

  From Chicago Tribune, ((A south suburban woman stabbed her 17-year-old to death during an argument in their home over ice cream, Cook County prosecutors said this afternoon. ))

Allegedly, this mother stabbed her son over some Famous Amos Ice Cream. I guess she won't get anything for Mother's Day. How can you do this to your son?

Anyway, the dumbest part is her statement to police. From the Huffington Post, ((Robin Erwin told police her son had walked into a knife she was holding, prompting her to call 911, the Sun-Times reports. The coroner's office later found her statement to be "inconsistent with medical findings," prompting prosecutors to seek murder charges. ))

Wait, that doesn't make sense unless it was pitch black and she didn't warn him she was holding the knife. It just seems a little heartless to make seem like your son tripped over something and fell on the knife you're holding. 

I generally don't walk into knives as a rule.  They tend to kill.