Need Advice for Home Alarm

["LFT" <lft@xxxxxxxx>]

Hi, I live in a city in the mid-Atlantic region.  It's an end of group
rowhouse in a neighborhood that's changing from working class/poor to a
middle class neighborhood.  Problem is for now there  is a criminal element
that lives here and many rental units.
I want to buy a home alarm to alert and call the police when a break in
occurs.  The house has three doors to the outside
and windows in the front and back.  Also, I've got a garage I'd like to
protect as well.  I don't know where to start with this.
Any help is greatly appreciated.

Thanks in advance,

Mike