Marco della Cava and Mike Stucka USA TODAY NETWORK Mass shootings in the United States jumped nearly 50% during 2020, a year that brought a pandemic, crippling unemployment, violent protests and idle youth. With COVID-19 cases falling and vaccines rolling out, some criminologists hope a rebounding economy and reopened schools will drive down the national numbers in 2021. Early results are promising, says Mark Bryant, founder of the nonprofit Gun Violence Archive, which tracks gun incident trends. In the first seven weeks of this year, there have been 63 mass shootings — defined as four or more people injured or killed in one incident — which, if that pace continues, would results in a drop from 2020, he said.