A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed. 

What "well regulated Militia" are Edward Charles Allaway, James Edward Pough, Carl Robert Brown, Omar Mateen, Robert A. Hawkins, James Oliver Huberty, Nathan Dunlap, George Hennard, Dylann Roof, Adam Lanza, Nidal Malik Hasan, Charles Whitman, Jeff Weise, Michael Carneal, Gang Lu, Patrick Sherrill, T.J. Lane, Barry Loukaitis, Amy Bishop, Esteban Santiago, Christopher Harper-Mercer, Gian Luigi Ferri, Jaylen Fryberg, Scott Evans Dekraai, Steven Kazmierczak, James Eagan Holmes, Michael McLendon, Jared Lee Loughner, Seung-Hui Cho, Elliot Rodger, Charles Carl Roberts IV, Rizwan Farook and Tashfeen Malik, Robert Lewis Dear, Mitchell Johnson and Andrew Golden, Aaron Alexis, Eric Harris and Dylan Klebold, Kip Kinkel, Patrick Edward Purdy, Gavin Eugene Long, Micah Xavier Johnson, Kyle Aaron Huff, and Stephen Paddock part of?