Of course we expect a mother to be upset in this Ferguson case. Certainly we have all been in situations where we are too close for comfort, it prevents us from understanding the full picture or taking in the reality.
The decision was made not to indict Officer Wilson because this is what the Grand Jury concluded based on the facts, the witnesses, the physical evidence, and other statements. They had the option of inditing him on a wide variety of charges including involuntary manslaughter. There simply was NO case to be made. No probable cause was found.