> The Detroit Police Department no longer responds routinely to house alarms, because 98% of house alarms are false. Detroit Police officers will respond ONLY to house alarms that can be VERIFIED as not being false alarms ... DPD recognizes four different ways that an alarm can be automatically verified ... An alarm system sends one signal from a door, window, or other perimeter/exterior sensor AND sends one signal from some sensor inside a house. An alarm system sends three signals from one or more interior sensors. An alarm system sends an audio signal that lets a company monitor hear an intruder. An alarm system sends a visual signal that lets a company monitor see an intruder.
> Do sound alarms deter only small burglars?
What deters non-small (organized?) burglars?