If I were to install window motion sensors, glass break sensors, door sensors, and cameras, I’ve basically got my own home security system. But how would you go about mimicking the remote monitoring functions that a company such as ADT or SimpliSafe would do?
The type where if your alarm goes off, you get a phone call and are asked for your code word, and if you give the incorrect code word, the police are summoned or whatever.
Maybe first check if it’s even legal to robo-call the police emergency line. I suppose with off-the-shelf systems that’s done by people in some callcenter who read the notification. In this case that’d be you. Or they’re somehow certified or have some agreement with the police… I don’t know the details. Technically it’d be possible. I’m running an Asterisk PBX server and hook into the dialplan with the REST API (that’d be ARI on the Asterisk side). That way Home Assistant can call me and make my landline phone ring twice once the laundry is done. And Asterisk can do arbitrary things. You could make it call you, play back some announcement, wait for your answer and process it and then call the police line and play back some pre-recorded message.
But you’d really need to talk to police and ask them about how to interface with them.