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.

First of all, those monitoring companies (at least where I live), send their own person, not the police. Maybe they call the police if they see that a break in is happening but first they check it out themselves first. So really you'd have to send yourself a notification (on iOS they have the emergency ones that always go through and loudly ring on your phone). Then you'd have to check it out yourself. Calling the police automatically every time sounds like a bad idea. At least with my system it would have been like 50 false alarms and no real alarms to the police over the last 15 years.