You are assuming the camera was wifi connected and not a stand alone system in a rural area.
A safer bet is that it was someone familiar to them and knew there was inadequate security.
No, I’m assuming they had a plain ol’ telephone land line and a modem dedicated to the camera system, the minimum spec for the desired function. No disrespect to the departed intended.
...and not placing any bets on who it might have been either, considering the times we live in. Coulda been any kind of criminals, any kind of terrorists, or coulda been any kind of “Cops”.