Investigations have singled out Pete Arredondo for the delayed police response to a 2022 school shooting in Texas. He is expected to appear in court for the first time on Monday.

© Tamir Kalifa for The New York Times

The teen suspect was questioned last year about online threats, though nothing conclusive emerged. Many local police departments lack the resources to take deeper looks at suspicious actors.

© Christian Monterrosa for The New York Times

Focusing on parental responsibility allows the state to shift blame from weapons laws to families.

Is the problem the man who gave his son a gun, or the gun?

Readers discuss gun laws, trying the suspect as an adult, defining mass shootings and more. Also: A view from AIPAC; an anti-family Republican Party.