Most of those units, at least in the US, have been converted to cellular data now.
To anwer ops question, without the manual in the panel box, you may have to see if there is a newer but compatible keypad but you would not likely be able to use the old equipment on the modern panels easily.
Edit: also +1 on Ademco panel








They are likely no trained to declare deceased status, so even though it may appear obvious, they are supposed to treat her as though alive. Thus declining medical attention could be legal grounds for murder.
I know most police organizations cannot declare it, nor can prison guards. So it would follow that legally ICE probably can’t.