said by mityfowl:
Alarms do nothing for most people
The police are minutes away when you have seconds
True, since most alarm systems are installed in a way that the alarm can not be heard from outside.
A siren and flashing light on the outside of the house is the way to go. That in itself will be a pretty damned good deterrent. In seconds the whole neighborhood will be alerted. The would-be thief isn't going to stick around.
Just be careful to avoid false alarms!