Motion detectors outside are ok for operating lights. but motion detectors INSIDE are designed to alarm (Wake folks up)
And as I said... The one thing a burgler fears most is not police, but a owner with a shotgun. So when the alarm goes off, Loudly state "Call the cops, I'll get the shotgun" Trust me, no self respecting burgler wants to find out that you really do have a shotgun and know how to use it.
Of course my idea of the perfect burglar alarm does not use bells, lights, sirens, buzzers or the like,,, It uses a digital recording, about 30 seconds of digital zeros (pure silence) followed by the sound of a shotgun being "racked" (readied for action)
As for letting the neighbors know about the burglar... Don't worry, he's going to do that on his way out