Secure the services of a reputable alarm company. Space detection methods (motion detectors) are excellent. Physical contact methods are fair, but tend to send false alarms. Any alarm system should include a battery failsafe back-up, smoke-sensing capability, read-out ability to check working of system, and a horn sounding device installed in attic through vent. In addition to the alarm sounding at the residence, your system should transmit a signal to the alarm company.
NOTE: The City requires an alarm permit. Contact the Denton Police Records division at (940) 349-7973. The permit is $5 per year. The permit gives emergency and contact information needed by the Police Department.