easy to identify. but dr. fisher, tell us about some of the psychological issues, ptsd. >> in any situation we have something beyond the scope of what we experience, we have the ability to experience post traumatic stress disorder. you can have symptoms from six months to years later. and what sets them off might be triggers. and when people see these he wants on the news it could be difficult. one thing that's coming to mind to me is the core spoent at sandy hook day and today's tragedy. it's a tragedy that some parents could be reminded of their tragedy going back to major newtown events. >> so the newtown victims could retraumatized from this? >> it's the events that went on.