AH but only After you have reinforced your doors and windows. Otherwise an alarm gets your local police to your house promptly after the bad guys have departed.
It may or may not scare off the teenage dunderhead.
Here's what actually happens....,
Entry is made = alarm is activiated...., 1 minute before audible alarm sounds because the system gives the resident one minute to reach the control panel to turn it off and not wake up the neighbors or alert the monitoring company.....
1 minute elapsed
After one minute, alarm sounds and alarm company calls house to make sure it's not a false alarm, IF the guy working for the alarm company for minimum wage is alert and diligent.....
2 minutes have elapsed....
Alarm company didn't get a response when they called or the person who answered didn't have the pass code. Police dispatching is called and police event is generated......
3 minutes have elapsed...
It's a quiet day so there are no other police emergencies that are more important, so the dispatcher radios the call to the officers in their cars....,
4 minutes have elapsed...,
IF the officers don't arrive in the next two minutes...,
6 minutes have elapsed, and the burglars are out of the house and moving away from the area on foot or to their car parked a block or two away, and then flee by car.....
So you reinforce the metal plate in your door jamb. You need a steel plate, not brass, and you need 4 steel screws at least 4" long..., since the vast majority of deadbolt systems from $20 - $80 or more, have a hopelessly useless plate that is only attached to the door jamb, and isn't anchored into the actual
door frame. 
There are a variety of methods of securing your windows too. THIS buys time for the police to respond since most systems will activate when the first attemtp to force the door fails. OFTEN a properly reenforced door (pennies compared to alarms and monitoring fees) will thwart a burglar, since they quickly give up.
AH but the reason burglary is sooo prevalent and home-invasion-robbery is much much more rare..., the burglars do take steps to ensure the dwelling isn't occupied. A classic one is for one to ring your doorbell for a good five minutes, while the other moves around back to listen. Can't be shooting through the door at the annoying person who isn't breaking the law by ringing your doorbell for five minutes.
Sometimes they pose as folks soliciting for business, and they ask your neighbors, "Is your neighbor next door home? Do you think he'd be interested? We give a good discount for referrals. What time do you think he will be home?" Your neighbor unwittingly tells them you're at work and won't be home until after 6, which probably means tomorrow the house will also be empty until 6.
Sometimes they look and say, "OH well if his big pickup isn't parked in the driveway, he's not there." (Sometimes they are legit employees of the roofing or gutter company, and do burglaries on the side)
It's not as simple as most people expect.
LD
