“None of the major shootings that have occurred in this country over the last few months or years that have outraged us, would gun laws have prevented them.”

— Sen. Marco Rubio (R-Fla.). interview on CBS’s “This Morning,” Dec. 4, 2015

We developed the following list of 12 mass shootings since 2012 listed in the Mother Jones database of U.S. mass shootings, with details obtained from various news and official reports. We will look at whether proposals might have made a difference in how the guns were obtained, or whether existing laws worked as intended.

Mass Shootings since 2012

Dec. 2, 2015: Syed Farook and Tashfeen Malik killed 14 people in San Bernardino, Calif., using a Smith & Wesson M&P AR-15 type rifle, a DPMS Panther Arms AR-15 type rifle, a Smith & Wesson semiautomatic pistol and a Llama semiautomatic pistol. The guns were purchased legally and the rifles were purchased…