How Well Do Crime and Violence Prevention Devices (E

How well do crime and violence prevention devices (e.g. security cameras and metal detectors) work to deter school violence incidents?

A) They work quite well? incidents have dropped since the mid 1990s.
B) They have not had an effect one way or the other? administrators like them, though.
C) They do not work? it's better to teach young children conflict resolution skills.
D) Metal detectors clearly work better than do security cameras and other devices.