Also, if you have wifi, a simple camera like Wyze can be used to monitor and record HD color video and can be viewed from your phone. If wifi is not available, try a trail cam. I have yet to get one myself but I do wish I could have see what killed my poor Henrietta.
I think everyone will have their own suggestions. I've been dealing with predators too, recently had my coop ripped apart by a bear so FYI, almost nothing is bear proof. However, using 1/4" hardware cloth that is screwed in using strips of wood over the hardware cloth is most effective against...