On a visceral level, it feels far too common. A week ago, conservative activist Charlie Kirk was assassinated while speaking at a college in Utah. That same day, a student opened fire at a Colorado high school, critically wounding two peers. Just two weeks earlier, a mass shooting at a Minnesota Catholic church killed two children and injured 21 others. Once again, a series of horrific, high-profile shootings has gripped the country and brought national focus to the issue of gun violence, especially as it relates to school safety and politically motivated attacks. NPR spoke with experts on mass shootings,...