A friend of mine stated to me recently that when shopping during the Holiday season, she was particularly uncomfortable with some of the people at the train station and on the sidewalks in Center City. She stated that she didn't feel comfortable in their midst. Some were talking to themselves, gesticulating, and appeared ungroomed and even unclean. She told me that she crossed the street, avoided eye contact, and was prepared to run, if necessary.
My response: Most people with mental illness are basically harmless and may be targets of violence themselves. Many, if not most, people who are mentally ill, and quite sick, and have never hurt anyone.
With that said, what about the people who have participated in mass gun violence? Sad, tragic, vicious attacks perpetrated on innocent men, women and children. Are these people mentally ill? It's easy to lump these individuals as mentally ill, and not address the issue of the gun problem, in general. We are still learning facts about the shooter in Las Vegas who killed 58 people and injured 851 people. What was his motive, his reasoning? We may never know. I don't have all of the facts, and I don't know if his family and/or friends noticed any aberrant behavior prior to the event committed on October 1st, 2017 that would provide clues surrounding that horrendous, heinous act.
But, I can write this. These horrific acts are the exception. During 1999 - 2015, according to the Nat'l. Center for Health Statistic, there were 198,760 homicides committed by a firearm. The 2016 American Psychiatric Association has written a report that less than 1% are committed by a person diagnosed with mental illness.
I believe that you/we should always be aware of our surroundings. Watch people's actions. If someone is acting in a strange, disruptive way, that doesn't mean they're mentally ill, but you should still be cautious.
And, if you know of someone in your family or circle of friends/acquantances who need help, don't hesitate to call your County Mental Health Clinic and speak to a Mental Health professional for guidance.