The amount of resources devoted to studying gun violence is paltry compared to its public health impact. Still, the evidence shows certain policies might help prevent mass shootings.

The school district in Buffalo, N.Y., announced Wednesday it would keep all school doors locked during the school day, and bar all unannounced visits to its buildings, including by students' parents.

The weapon used to carry out the mass shooting in Uvalde, Texas, is one all too familiar to Americans and lawmakers who have witnessed mass shootings occur over the past decade.

Prosecutors had asked for the maximum term of 20 years in prison for Duggar, whose family was the focus of TLC's 19 Kids and Counting. Duggar's lawyers maintain his innocence and say they'll appeal.