Oddly enough Freidman seems to have forgotten the last mass murderers.  The ones with Pakistani connections who killed so many in San Bernadino, California in 2015 less than two years ago. 

"14 people were killed and 22 others were seriously injured in an attack consisting of a mass shooting and an attempted bombing."  "expressing a commitment to jihadism and martyrdom in private messages"

The reason that one didn't result in what he wants done today is because California already had all the gun laws allowed under the 2nd Amendment and-it-did-not-prevent-the-massacre!