What Is Causing This Violence?

I haven't written much lately because it seems all the news that is reported is very disheartening...  killer cyclones, volcanic eruptions, school shootings, restaurant bombings, and the crazy man in the Oval Office doing his best to make our great country the laughing stock of the world.
   What is causing a single person to take a weapon and kill multiple people?  Why is this type of behavior, seemingly, becoming normal?  What is causing people, both young and old, to destroy multiple lives?  As someone who wants to, but is afraid to try to commit suicide (for fear of not doing the deed effectively), I cannot grasp the need to kill others... 
   I cannot imagine why two seemingly young(ish) men would take a home-made bomb into a family restaurant in Mississauga, Ontario, Canada and set it off during two private parties - injuring 12 and causing critical injuries to three people.  The three have had surgery and are now upgraded to serious condition.  Canada law enforcement is looking for the two men, who were caught on video, who carried the bomb into Bombay Bhel and then left.
   Why would a student in Noblesville, Indiana ask to to to the restroom during a test in his science class, and return with two handguns, and start shooting?  Thank goodness the science teacher, Jason Seaman, is seemingly fearless.  He charged the student, who had already shot and wounded a female student, taking three bullets in his chest.  Mr Seaman tackled the gunman, and told the rest of the students to run away.  He and the female student survived, and the shooter is under arrest.  He is a true hero!

This photo is from the University of Southern Illinois, which science teacher Jason Seaman attended.

   Natural events, we/I have no way of controlling, but I still feel badly for the people afflicted with these events.

   The man in the Oval Office of the White House - well, all I can do is hope he will soon be impeached and/or imprisoned.  He is using his position as a way to stuff his own pockets (and those of his family) with money that is illegally gained.  His stupid little dancing and one-upmanship game with North Korea's Kim Jong Un is senseless.  His sudden caring about ZTE, a Chinese company banned from selling in the US due to spying and stealing in the past, is only tied to the $500,000 the Chinese government contributed to one of his building projects in a third country....

   Just thinking about that man makes me want to take a shower in bleach to remove the slime...