Many municipalities have codes that state if a fire alarm is sounding they show up regardless if home owner cancels or not- Comcast doesnt control this. Also, the laws are different depending on where you live. As far as police, if Central Station can't reach a customer in the event the alarm is sounding they are sending the police. It's important to save the this number
1-800-633-2677 in your phone as "Alarm Co" or whatever alerts you that this is a call to answer.