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.