Which of the Following Statements About School Shooters Is True

Which of the following statements about school shooters is true?

A) About 50 percent of all reported school shooters are minority-group members.
B) In most cases,there was no action (e.g. ,no notes or threats) indicating risk of violence prior to the school shootings.
C) Most school shooters have a significant,underlying mental disorder.
D) School shooters typically develop a plan of attack well in advance.