The U.S. was rocked by hundreds of mass shootings in 2022. There is no consensus on the definition of a mass shooting, making it harder to document the scale of the country's gun violence crisis. The Gun Violence Archive, a nonprofit research group, defines a mass shooting as four or more people shot in a single incident not including the shooter. At least 639 mass shootings have taken place in the U.S. this year, according to the nonprofit. Here is a list of 10 of the most notable mass shootings of 2022: Sacramento, California - April 3 Six people were...