Alarm systems are good, and they will generally alert either yourself or a private security company if they are tripped. The private security company will quickly assess the situation and choose to contact the police or not. If you are the one being notified through your computer or smart phone, you will then need to make a quick determination if there is an actual intruder or if it was tripped by something else. No matter what, these determinations are being made after the person has gained entry, and are designed to assist authorities in catching the person either before they leave, or getting them on camera to provide police with a description. These measures are not designed to keep people out of the house, they are designed to help catch them once they have entered.
A better method of security is prevention. This means utilizing systems that actually stop the person from ever entering the home in the first place, instead of just telling you once they are inside. The best method of securing a home is the installation of iron security doors into the entryways, and placing iron bar coverings over the windows. This will make it so that a thief would need to take the time and make the noise necessary to cut through iron in order to gain access. Thieves generally smash a window or kick in a door in order to gain easy access, and iron security doors make this nearly impossible. It would take a long time to cut through the iron, and most bad guys are not going to spend the time or effort to get in, and instead will move to the next easy target. Prevention of access is actual safety, whereas an alarm just functions to try and stop them once they are committing a crime. Because Las Vegas is seeing a rise in crime as our population grows, looking into protecting yourself and your home is a good idea. Don't be the victim, be the one that they decide not to victimize.