I looked up a couple of things about people shooting people:

Deaths in America caused by a Gun:

The year 2014, the most recent statistics available...

• There were just over 33,000 Gun deaths in America in 2014
• 60% of them were suicides.........ie 19,982
• 3% were accidental.....................         990
• 4% were justified........................      1,320
• 33% were Homicides..................    10,840*

             *80% of Homicides were Gang Related...ie    8712

             * That leaves 2178 non Gang Related Homicides commited

                with a Gun in a country of 300million plus people.

source: Center for Disease Control 

                      

                                             -------------------------------------

# of Mass Shooting incidents in America (3 or more killed in one incident)

Years 1982 thru 2016

Per Presidential Term:

•  Reagan  11
• Bush       12
• Clinton   23
• Bush Jr   16
• Obama    34

TOTAL            96

source: Mother Jones Investigations http://www.motherjones.com/politics/2012/12/mass-shootings-mother-jones-full-data