This story has been updated in light of the San Bernardino shootings.
There have been at least 351 mass shootings so far this year. A mass shooting is defined as incidents in which 4 or more are killed or injured by gunfire.
There were at least 12 mass shootings in the U.S. last week so far, counting the Colorado Springs shooting. That shooting would also be the 2nd mass shooting in Colorado Springs this month.